---
_id: '59276'
abstract:
- lang: eng
text: Stress plays a crucial role in thin films and layered systems, and thus significantly
influences the material's electrical, mechanical and (nonlinear) optical responses.
Despite lithium niobate's wide applicability as a nonlinear optical material,
the impact of mechanical stress on its nonlinear optical properties is not well
characterized. In this work, we systematically study both experimentally and theoretically,
the nonlinear optical responses of thin film lithium niobate (TFLN) single crystals.
Compressive and tensile stress is applied in our experiment using a piezodriven
strain cell. We then record the second-harmonic-generated (SHG) response in back-reflection
geometry, and compare these results to theoretical modeling using density functional
theory (DFT). Both methods consistently reveal that uniaxial stress induces changes
of the nonlinear optical susceptibility of certain tensor elements on the order
of up to 1 pm/(V GPa). The exact value depends on the tensor element that is addressed
in our SHG analysis, on the crystal orientation, and also whether using compressive
or tensile stresses. Furthermore, a lowering of the crystal symmetry when applying
stress along the x
or y
crystallographic axes is observed by the appearance of new nonlinear optical tensor
elements within the strained crystals.
article_number: '064109'
author:
- first_name: Mike N.
full_name: Pionteck, Mike N.
last_name: Pionteck
- first_name: Matthias
full_name: Roeper, Matthias
last_name: Roeper
- first_name: Boris
full_name: Koppitz, Boris
last_name: Koppitz
- first_name: Samuel D.
full_name: Seddon, Samuel D.
last_name: Seddon
- first_name: Michael
full_name: Rüsing, Michael
id: '22501'
last_name: Rüsing
orcid: 0000-0003-4682-4577
- first_name: Laura
full_name: Padberg, Laura
id: '40300'
last_name: Padberg
- first_name: Christof
full_name: Eigner, Christof
id: '13244'
last_name: Eigner
orcid: https://orcid.org/0000-0002-5693-3083
- first_name: Christine
full_name: Silberhorn, Christine
id: '26263'
last_name: Silberhorn
- first_name: Simone
full_name: Sanna, Simone
last_name: Sanna
- first_name: Lukas M.
full_name: Eng, Lukas M.
last_name: Eng
citation:
ama: Pionteck MN, Roeper M, Koppitz B, et al. Second-order nonlinear piezo-optic
properties of single crystal lithium niobate thin films. Physical Review B.
2025;111(6). doi:10.1103/physrevb.111.064109
apa: Pionteck, M. N., Roeper, M., Koppitz, B., Seddon, S. D., Rüsing, M., Padberg,
L., Eigner, C., Silberhorn, C., Sanna, S., & Eng, L. M. (2025). Second-order
nonlinear piezo-optic properties of single crystal lithium niobate thin films.
Physical Review B, 111(6), Article 064109. https://doi.org/10.1103/physrevb.111.064109
bibtex: '@article{Pionteck_Roeper_Koppitz_Seddon_Rüsing_Padberg_Eigner_Silberhorn_Sanna_Eng_2025,
title={Second-order nonlinear piezo-optic properties of single crystal lithium
niobate thin films}, volume={111}, DOI={10.1103/physrevb.111.064109},
number={6064109}, journal={Physical Review B}, publisher={American Physical Society
(APS)}, author={Pionteck, Mike N. and Roeper, Matthias and Koppitz, Boris and
Seddon, Samuel D. and Rüsing, Michael and Padberg, Laura and Eigner, Christof
and Silberhorn, Christine and Sanna, Simone and Eng, Lukas M.}, year={2025} }'
chicago: Pionteck, Mike N., Matthias Roeper, Boris Koppitz, Samuel D. Seddon, Michael
Rüsing, Laura Padberg, Christof Eigner, Christine Silberhorn, Simone Sanna, and
Lukas M. Eng. “Second-Order Nonlinear Piezo-Optic Properties of Single Crystal
Lithium Niobate Thin Films.” Physical Review B 111, no. 6 (2025). https://doi.org/10.1103/physrevb.111.064109.
ieee: 'M. N. Pionteck et al., “Second-order nonlinear piezo-optic properties
of single crystal lithium niobate thin films,” Physical Review B, vol.
111, no. 6, Art. no. 064109, 2025, doi: 10.1103/physrevb.111.064109.'
mla: Pionteck, Mike N., et al. “Second-Order Nonlinear Piezo-Optic Properties of
Single Crystal Lithium Niobate Thin Films.” Physical Review B, vol. 111,
no. 6, 064109, American Physical Society (APS), 2025, doi:10.1103/physrevb.111.064109.
short: M.N. Pionteck, M. Roeper, B. Koppitz, S.D. Seddon, M. Rüsing, L. Padberg,
C. Eigner, C. Silberhorn, S. Sanna, L.M. Eng, Physical Review B 111 (2025).
date_created: 2025-04-02T16:21:47Z
date_updated: 2025-04-02T16:24:47Z
department:
- _id: '15'
- _id: '623'
- _id: '288'
doi: 10.1103/physrevb.111.064109
intvolume: ' 111'
issue: '6'
language:
- iso: eng
publication: Physical Review B
publication_identifier:
issn:
- 2469-9950
- 2469-9969
publication_status: published
publisher: American Physical Society (APS)
quality_controlled: '1'
status: public
title: Second-order nonlinear piezo-optic properties of single crystal lithium niobate
thin films
type: journal_article
user_id: '22501'
volume: 111
year: '2025'
...
---
_id: '58642'
abstract:
- lang: eng
text: We present a cost-effective self-assembly method to fabricate low-density
dimer NPs in an NPoM architecture, using the M13 phage as a spacer layer. This
will enable the development of dynamic plasmonic devices and advanced sensing
applications.
article_type: original
author:
- first_name: Vasanthan
full_name: Devaraj, Vasanthan
id: '103814'
last_name: Devaraj
- first_name: Isaac Azahel
full_name: Ruiz Alvarado, Isaac Azahel
id: '79462'
last_name: Ruiz Alvarado
orcid: 0000-0002-4710-1170
- first_name: Jong-Min
full_name: Lee, Jong-Min
last_name: Lee
- first_name: Jin-Woo
full_name: Oh, Jin-Woo
last_name: Oh
- first_name: Uwe
full_name: Gerstmann, Uwe
id: '171'
last_name: Gerstmann
orcid: 0000-0002-4476-223X
- first_name: Wolf Gero
full_name: Schmidt, Wolf Gero
id: '468'
last_name: Schmidt
orcid: 0000-0002-2717-5076
- first_name: Thomas
full_name: Zentgraf, Thomas
id: '30525'
last_name: Zentgraf
orcid: 0000-0002-8662-1101
citation:
ama: Devaraj V, Ruiz Alvarado IA, Lee J-M, et al. Self-assembly of isolated plasmonic
dimers with sub-5 nm gaps on a metallic mirror. Nanoscale Horizons. 2025;10:537-548.
doi:10.1039/d4nh00546e
apa: Devaraj, V., Ruiz Alvarado, I. A., Lee, J.-M., Oh, J.-W., Gerstmann, U., Schmidt,
W. G., & Zentgraf, T. (2025). Self-assembly of isolated plasmonic dimers with
sub-5 nm gaps on a metallic mirror. Nanoscale Horizons, 10, 537–548.
https://doi.org/10.1039/d4nh00546e
bibtex: '@article{Devaraj_Ruiz Alvarado_Lee_Oh_Gerstmann_Schmidt_Zentgraf_2025,
title={Self-assembly of isolated plasmonic dimers with sub-5 nm gaps on a metallic
mirror}, volume={10}, DOI={10.1039/d4nh00546e},
journal={Nanoscale Horizons}, publisher={Royal Society of Chemistry (RSC)}, author={Devaraj,
Vasanthan and Ruiz Alvarado, Isaac Azahel and Lee, Jong-Min and Oh, Jin-Woo and
Gerstmann, Uwe and Schmidt, Wolf Gero and Zentgraf, Thomas}, year={2025}, pages={537–548}
}'
chicago: 'Devaraj, Vasanthan, Isaac Azahel Ruiz Alvarado, Jong-Min Lee, Jin-Woo
Oh, Uwe Gerstmann, Wolf Gero Schmidt, and Thomas Zentgraf. “Self-Assembly of Isolated
Plasmonic Dimers with Sub-5 Nm Gaps on a Metallic Mirror.” Nanoscale Horizons
10 (2025): 537–48. https://doi.org/10.1039/d4nh00546e.'
ieee: 'V. Devaraj et al., “Self-assembly of isolated plasmonic dimers with
sub-5 nm gaps on a metallic mirror,” Nanoscale Horizons, vol. 10, pp. 537–548,
2025, doi: 10.1039/d4nh00546e.'
mla: Devaraj, Vasanthan, et al. “Self-Assembly of Isolated Plasmonic Dimers with
Sub-5 Nm Gaps on a Metallic Mirror.” Nanoscale Horizons, vol. 10, Royal
Society of Chemistry (RSC), 2025, pp. 537–48, doi:10.1039/d4nh00546e.
short: V. Devaraj, I.A. Ruiz Alvarado, J.-M. Lee, J.-W. Oh, U. Gerstmann, W.G. Schmidt,
T. Zentgraf, Nanoscale Horizons 10 (2025) 537–548.
date_created: 2025-02-14T08:13:10Z
date_updated: 2025-07-09T14:04:39Z
department:
- _id: '15'
- _id: '230'
- _id: '289'
- _id: '623'
- _id: '35'
- _id: '295'
- _id: '170'
- _id: '429'
- _id: '27'
doi: 10.1039/d4nh00546e
intvolume: ' 10'
language:
- iso: eng
page: 537-548
project:
- _id: '53'
grant_number: '231447078'
name: 'TRR 142: TRR 142 - Maßgeschneiderte nichtlineare Photonik: Von grundlegenden
Konzepten zu funktionellen Strukturen'
- _id: '168'
grant_number: '231447078'
name: 'TRR 142 - B07: TRR 142 - Polaronen-Einfluss auf die optischen Eigenschaften
von Lithiumniobat (B07*)'
- _id: '55'
name: 'TRR 142 - B: TRR 142 - Project Area B'
- _id: '445'
grant_number: '367360193'
name: Hochleistungsrechner Noctua in Paderborn
- _id: '52'
name: 'PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing'
publication: Nanoscale Horizons
publication_identifier:
issn:
- 2055-6756
- 2055-6764
publication_status: published
publisher: Royal Society of Chemistry (RSC)
quality_controlled: '1'
status: public
title: Self-assembly of isolated plasmonic dimers with sub-5 nm gaps on a metallic
mirror
type: journal_article
user_id: '16199'
volume: 10
year: '2025'
...
---
_id: '60587'
author:
- first_name: Timon
full_name: Schapeler, Timon
id: '55629'
last_name: Schapeler
orcid: 0000-0001-7652-1716
- first_name: Fabian
full_name: Schlue, Fabian
id: '63579'
last_name: Schlue
- first_name: Michael
full_name: Stefszky, Michael
id: '42777'
last_name: Stefszky
- first_name: Benjamin
full_name: Brecht, Benjamin
id: '27150'
last_name: Brecht
orcid: '0000-0003-4140-0556 '
- first_name: Christine
full_name: Silberhorn, Christine
id: '26263'
last_name: Silberhorn
- first_name: Tim
full_name: Bartley, Tim
id: '49683'
last_name: Bartley
citation:
ama: 'Schapeler T, Schlue F, Stefszky M, Brecht B, Silberhorn C, Bartley T. Optimizing
photon-number resolution with superconducting nanowire multi-photon detectors.
In: Itzler MA, McIntosh KA, Bienfang JC, eds. Advanced Photon Counting Techniques
XIX. SPIE; 2025. doi:10.1117/12.3054905'
apa: Schapeler, T., Schlue, F., Stefszky, M., Brecht, B., Silberhorn, C., &
Bartley, T. (2025). Optimizing photon-number resolution with superconducting nanowire
multi-photon detectors. In M. A. Itzler, K. A. McIntosh, & J. C. Bienfang
(Eds.), Advanced Photon Counting Techniques XIX. SPIE. https://doi.org/10.1117/12.3054905
bibtex: '@inproceedings{Schapeler_Schlue_Stefszky_Brecht_Silberhorn_Bartley_2025,
title={Optimizing photon-number resolution with superconducting nanowire multi-photon
detectors}, DOI={10.1117/12.3054905},
booktitle={Advanced Photon Counting Techniques XIX}, publisher={SPIE}, author={Schapeler,
Timon and Schlue, Fabian and Stefszky, Michael and Brecht, Benjamin and Silberhorn,
Christine and Bartley, Tim}, editor={Itzler, Mark A. and McIntosh, K. Alex and
Bienfang, Joshua C.}, year={2025} }'
chicago: Schapeler, Timon, Fabian Schlue, Michael Stefszky, Benjamin Brecht, Christine
Silberhorn, and Tim Bartley. “Optimizing Photon-Number Resolution with Superconducting
Nanowire Multi-Photon Detectors.” In Advanced Photon Counting Techniques XIX,
edited by Mark A. Itzler, K. Alex McIntosh, and Joshua C. Bienfang. SPIE, 2025.
https://doi.org/10.1117/12.3054905.
ieee: 'T. Schapeler, F. Schlue, M. Stefszky, B. Brecht, C. Silberhorn, and T. Bartley,
“Optimizing photon-number resolution with superconducting nanowire multi-photon
detectors,” in Advanced Photon Counting Techniques XIX, 2025, doi: 10.1117/12.3054905.'
mla: Schapeler, Timon, et al. “Optimizing Photon-Number Resolution with Superconducting
Nanowire Multi-Photon Detectors.” Advanced Photon Counting Techniques XIX,
edited by Mark A. Itzler et al., SPIE, 2025, doi:10.1117/12.3054905.
short: 'T. Schapeler, F. Schlue, M. Stefszky, B. Brecht, C. Silberhorn, T. Bartley,
in: M.A. Itzler, K.A. McIntosh, J.C. Bienfang (Eds.), Advanced Photon Counting
Techniques XIX, SPIE, 2025.'
date_created: 2025-07-11T09:18:09Z
date_updated: 2025-07-11T09:22:11Z
department:
- _id: '15'
- _id: '623'
doi: 10.1117/12.3054905
editor:
- first_name: Mark A.
full_name: Itzler, Mark A.
last_name: Itzler
- first_name: K. Alex
full_name: McIntosh, K. Alex
last_name: McIntosh
- first_name: Joshua C.
full_name: Bienfang, Joshua C.
last_name: Bienfang
language:
- iso: eng
project:
- _id: '239'
call_identifier: ERC
grant_number: '101042399'
name: 'QuESADILLA: ERC-Grant: QuESADILLA: Quantum Engineering Superconducting Array
Detectors in Low-Light Applications'
- _id: '191'
grant_number: 13N16103
name: 'PhoQuant--QCTest: PhoQuant: Photonische Quantencomputer - Quantencomputing
Testplattform'
publication: Advanced Photon Counting Techniques XIX
publication_status: published
publisher: SPIE
status: public
title: Optimizing photon-number resolution with superconducting nanowire multi-photon
detectors
type: conference
user_id: '55629'
year: '2025'
...
---
_id: '61110'
abstract:
- lang: eng
text: 'By analyzing the physics of multi-photon absorption in superconducting
nanowire single-photon detectors (SNSPDs), we identify physical components of
jitter. From this, we formulate a quantitative physical model of the multi-photon
detector response that combines the local detection mechanism and local fluctuations
(hotspot formation and intrinsic jitter) with the thermoelectric dynamics of resistive
domains. Our model provides an excellent description of the arrival-time histogram
of a commercial SNSPD across several orders of magnitude, both in arrival-time
probability and across mean photon number. This is achieved with just three fitting
parameters: the scaling of the mean arrival time of voltage response pulses, as
well as the Gaussian and exponential jitter components. Our findings have important
implications for photon-number-resolving detector design, as well as applications
requiring low jitter, such as light detection and ranging (LIDAR).'
article_number: '086113'
article_type: original
author:
- first_name: Mariia
full_name: Sidorova, Mariia
last_name: Sidorova
- first_name: Timon
full_name: Schapeler, Timon
id: '55629'
last_name: Schapeler
orcid: 0000-0001-7652-1716
- first_name: Alexej D.
full_name: Semenov, Alexej D.
last_name: Semenov
- first_name: Fabian
full_name: Schlue, Fabian
id: '63579'
last_name: Schlue
- first_name: Michael
full_name: Stefszky, Michael
id: '42777'
last_name: Stefszky
- first_name: Benjamin
full_name: Brecht, Benjamin
id: '27150'
last_name: Brecht
orcid: '0000-0003-4140-0556 '
- first_name: Christine
full_name: Silberhorn, Christine
id: '26263'
last_name: Silberhorn
- first_name: Tim
full_name: Bartley, Tim
id: '49683'
last_name: Bartley
citation:
ama: Sidorova M, Schapeler T, Semenov AD, et al. Jitter in photon-number-resolved
detection by superconducting nanowires. APL Photonics. 2025;10(8). doi:10.1063/5.0273752
apa: Sidorova, M., Schapeler, T., Semenov, A. D., Schlue, F., Stefszky, M., Brecht,
B., Silberhorn, C., & Bartley, T. (2025). Jitter in photon-number-resolved
detection by superconducting nanowires. APL Photonics, 10(8), Article
086113. https://doi.org/10.1063/5.0273752
bibtex: '@article{Sidorova_Schapeler_Semenov_Schlue_Stefszky_Brecht_Silberhorn_Bartley_2025,
title={Jitter in photon-number-resolved detection by superconducting nanowires},
volume={10}, DOI={10.1063/5.0273752},
number={8086113}, journal={APL Photonics}, publisher={AIP Publishing}, author={Sidorova,
Mariia and Schapeler, Timon and Semenov, Alexej D. and Schlue, Fabian and Stefszky,
Michael and Brecht, Benjamin and Silberhorn, Christine and Bartley, Tim}, year={2025}
}'
chicago: Sidorova, Mariia, Timon Schapeler, Alexej D. Semenov, Fabian Schlue, Michael
Stefszky, Benjamin Brecht, Christine Silberhorn, and Tim Bartley. “Jitter in Photon-Number-Resolved
Detection by Superconducting Nanowires.” APL Photonics 10, no. 8 (2025).
https://doi.org/10.1063/5.0273752.
ieee: 'M. Sidorova et al., “Jitter in photon-number-resolved detection by
superconducting nanowires,” APL Photonics, vol. 10, no. 8, Art. no. 086113,
2025, doi: 10.1063/5.0273752.'
mla: Sidorova, Mariia, et al. “Jitter in Photon-Number-Resolved Detection by Superconducting
Nanowires.” APL Photonics, vol. 10, no. 8, 086113, AIP Publishing, 2025,
doi:10.1063/5.0273752.
short: M. Sidorova, T. Schapeler, A.D. Semenov, F. Schlue, M. Stefszky, B. Brecht,
C. Silberhorn, T. Bartley, APL Photonics 10 (2025).
date_created: 2025-09-01T11:12:19Z
date_updated: 2025-09-02T10:47:08Z
department:
- _id: '623'
- _id: '15'
doi: 10.1063/5.0273752
external_id:
arxiv:
- arXiv:2503.17146
intvolume: ' 10'
issue: '8'
keyword:
- Jitter
- PNR
- SNSPD
language:
- iso: eng
main_file_link:
- open_access: '1'
oa: '1'
project:
- _id: '191'
name: 'PhoQuant: Photonische Quantencomputer - Quantencomputing Testplattform'
- _id: '239'
name: 'ERC-Grant: QuESADILLA: Quantum Engineering Superconducting Array Detectors
in Low-Light Applications'
publication: APL Photonics
publication_identifier:
issn:
- 2378-0967
publication_status: published
publisher: AIP Publishing
status: public
title: Jitter in photon-number-resolved detection by superconducting nanowires
type: journal_article
user_id: '55629'
volume: 10
year: '2025'
...
---
_id: '61245'
article_number: '032404'
author:
- first_name: Franziska
full_name: Barkhausen, Franziska
id: '63631'
last_name: Barkhausen
- first_name: Laura
full_name: Ares Santos, Laura
last_name: Ares Santos
- first_name: Stefan
full_name: Schumacher, Stefan
id: '27271'
last_name: Schumacher
orcid: 0000-0003-4042-4951
- first_name: Jan
full_name: Sperling, Jan
id: '75127'
last_name: Sperling
orcid: 0000-0002-5844-3205
citation:
ama: 'Barkhausen F, Ares Santos L, Schumacher S, Sperling J. Entanglement between
dependent degrees of freedom: Quasiparticle correlations. Physical Review A.
2025;111(3). doi:10.1103/physreva.111.032404'
apa: 'Barkhausen, F., Ares Santos, L., Schumacher, S., & Sperling, J. (2025).
Entanglement between dependent degrees of freedom: Quasiparticle correlations.
Physical Review A, 111(3), Article 032404. https://doi.org/10.1103/physreva.111.032404'
bibtex: '@article{Barkhausen_Ares Santos_Schumacher_Sperling_2025, title={Entanglement
between dependent degrees of freedom: Quasiparticle correlations}, volume={111},
DOI={10.1103/physreva.111.032404},
number={3032404}, journal={Physical Review A}, publisher={American Physical Society
(APS)}, author={Barkhausen, Franziska and Ares Santos, Laura and Schumacher, Stefan
and Sperling, Jan}, year={2025} }'
chicago: 'Barkhausen, Franziska, Laura Ares Santos, Stefan Schumacher, and Jan Sperling.
“Entanglement between Dependent Degrees of Freedom: Quasiparticle Correlations.”
Physical Review A 111, no. 3 (2025). https://doi.org/10.1103/physreva.111.032404.'
ieee: 'F. Barkhausen, L. Ares Santos, S. Schumacher, and J. Sperling, “Entanglement
between dependent degrees of freedom: Quasiparticle correlations,” Physical
Review A, vol. 111, no. 3, Art. no. 032404, 2025, doi: 10.1103/physreva.111.032404.'
mla: 'Barkhausen, Franziska, et al. “Entanglement between Dependent Degrees of Freedom:
Quasiparticle Correlations.” Physical Review A, vol. 111, no. 3, 032404,
American Physical Society (APS), 2025, doi:10.1103/physreva.111.032404.'
short: F. Barkhausen, L. Ares Santos, S. Schumacher, J. Sperling, Physical Review
A 111 (2025).
date_created: 2025-09-12T10:37:34Z
date_updated: 2025-09-12T10:42:16Z
department:
- _id: '15'
- _id: '170'
- _id: '297'
- _id: '706'
- _id: '35'
- _id: '230'
- _id: '623'
- _id: '429'
doi: 10.1103/physreva.111.032404
intvolume: ' 111'
issue: '3'
language:
- iso: eng
project:
- _id: '53'
name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten
zu funktionellen Strukturen'
- _id: '54'
name: TRR 142 - Project Area A
- _id: '56'
name: TRR 142 - Project Area C
- _id: '61'
name: 'TRR 142; TP A04: Nichtlineare Quantenprozesstomographie und Photonik mit
Polaritonen in Mikrokavitäten'
- _id: '174'
name: 'TRR 142 ; TP: C10: Erzeugung und Charakterisierung von Quantenlicht in nichtlinearen
Systemen: Eine theoretische Analyse'
- _id: '266'
name: 'PhoQC: Photonisches Quantencomputing'
publication: Physical Review A
publication_identifier:
issn:
- 2469-9926
- 2469-9934
publication_status: published
publisher: American Physical Society (APS)
status: public
title: 'Entanglement between dependent degrees of freedom: Quasiparticle correlations'
type: journal_article
user_id: '16199'
volume: 111
year: '2025'
...
---
_id: '61338'
abstract:
- lang: eng
text: Conductive ferroelectric domain walls (DWs) represent a promising topical
system for the development of nanoelectronic components and device sensors to
be operational at elevated temperatures. DWs show very different properties as
compared to their hosting bulk crystal, in particular with respect to the high
local electrical conductivity. The objective of this work is to demonstrate DW
conductivity up to temperatures as high as 400 °C which extends previous studies
significantly. Experimental investigation of the DW conductivity of charged, inclined
DWs is performed using 5 mol % MgO-doped lithium niobate single crystals. Current–voltage
( ) curves are determined by DC electrometer measurements and impedance spectroscopy
and found to be identical. Moreover, impedance spectroscopy enables to recognize
artifacts such as damaged electrodes. Temperature dependent measurements over
repeated heating cycles reveal two distinct thermal activation energies for a
given DW, with the higher of the activation energies only measured at higher temperatures.
Depending on the specific sample, the higher activation energy is found above
160 °C to 230 °C. This suggests, in turn, that more than one type of defect/polaron
is involved, and that the dominant transport mechanism changes with increasing
temperature. First principles atomistic modeling suggests that the conductivity
of inclined domain walls cannot be solely explained by the formation of a 2D carrier
gas and must be supported by hopping processes. This holds true even at temperatures
as high as 400 °C. Our investigations underline the potential to extend DW current
based nanoelectronic and sensor applications even into the so-far unexplored temperature
range up to 400 °C.
article_number: '116949'
article_type: original
author:
- first_name: Hendrik
full_name: Wulfmeier, Hendrik
last_name: Wulfmeier
- first_name: Uliana
full_name: Yakhnevych, Uliana
last_name: Yakhnevych
- first_name: Cornelius
full_name: Boekhoff, Cornelius
last_name: Boekhoff
- first_name: Allan
full_name: Diima, Allan
last_name: Diima
- first_name: Marlo
full_name: Kunzner, Marlo
last_name: Kunzner
- first_name: Leonard M.
full_name: Verhoff, Leonard M.
last_name: Verhoff
- first_name: Jonas
full_name: Paul, Jonas
last_name: Paul
- first_name: Julius
full_name: Ratzenberger, Julius
last_name: Ratzenberger
- first_name: Elke
full_name: Beyreuther, Elke
last_name: Beyreuther
- first_name: Joshua
full_name: Gössel, Joshua
last_name: Gössel
- first_name: Iuliia
full_name: Kiseleva, Iuliia
last_name: Kiseleva
- first_name: Michael
full_name: Rüsing, Michael
id: '22501'
last_name: Rüsing
orcid: 0000-0003-4682-4577
- first_name: Simone
full_name: Sanna, Simone
last_name: Sanna
- first_name: Lukas M.
full_name: Eng, Lukas M.
last_name: Eng
- first_name: Holger
full_name: Fritze, Holger
last_name: Fritze
citation:
ama: Wulfmeier H, Yakhnevych U, Boekhoff C, et al. Demonstration of domain wall
current in MgO-doped lithium niobate single crystals up to 400°C. Solid State
Ionics. 2025;429. doi:10.1016/j.ssi.2025.116949
apa: Wulfmeier, H., Yakhnevych, U., Boekhoff, C., Diima, A., Kunzner, M., Verhoff,
L. M., Paul, J., Ratzenberger, J., Beyreuther, E., Gössel, J., Kiseleva, I., Rüsing,
M., Sanna, S., Eng, L. M., & Fritze, H. (2025). Demonstration of domain wall
current in MgO-doped lithium niobate single crystals up to 400°C. Solid State
Ionics, 429, Article 116949. https://doi.org/10.1016/j.ssi.2025.116949
bibtex: '@article{Wulfmeier_Yakhnevych_Boekhoff_Diima_Kunzner_Verhoff_Paul_Ratzenberger_Beyreuther_Gössel_et
al._2025, title={Demonstration of domain wall current in MgO-doped lithium niobate
single crystals up to 400°C}, volume={429}, DOI={10.1016/j.ssi.2025.116949},
number={116949}, journal={Solid State Ionics}, publisher={Elsevier BV}, author={Wulfmeier,
Hendrik and Yakhnevych, Uliana and Boekhoff, Cornelius and Diima, Allan and Kunzner,
Marlo and Verhoff, Leonard M. and Paul, Jonas and Ratzenberger, Julius and Beyreuther,
Elke and Gössel, Joshua and et al.}, year={2025} }'
chicago: Wulfmeier, Hendrik, Uliana Yakhnevych, Cornelius Boekhoff, Allan Diima,
Marlo Kunzner, Leonard M. Verhoff, Jonas Paul, et al. “Demonstration of Domain
Wall Current in MgO-Doped Lithium Niobate Single Crystals up to 400°C.” Solid
State Ionics 429 (2025). https://doi.org/10.1016/j.ssi.2025.116949.
ieee: 'H. Wulfmeier et al., “Demonstration of domain wall current in MgO-doped
lithium niobate single crystals up to 400°C,” Solid State Ionics, vol.
429, Art. no. 116949, 2025, doi: 10.1016/j.ssi.2025.116949.'
mla: Wulfmeier, Hendrik, et al. “Demonstration of Domain Wall Current in MgO-Doped
Lithium Niobate Single Crystals up to 400°C.” Solid State Ionics, vol.
429, 116949, Elsevier BV, 2025, doi:10.1016/j.ssi.2025.116949.
short: H. Wulfmeier, U. Yakhnevych, C. Boekhoff, A. Diima, M. Kunzner, L.M. Verhoff,
J. Paul, J. Ratzenberger, E. Beyreuther, J. Gössel, I. Kiseleva, M. Rüsing, S.
Sanna, L.M. Eng, H. Fritze, Solid State Ionics 429 (2025).
date_created: 2025-09-17T16:18:18Z
date_updated: 2025-09-17T16:19:51Z
department:
- _id: '15'
- _id: '288'
- _id: '623'
doi: 10.1016/j.ssi.2025.116949
intvolume: ' 429'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.1016/j.ssi.2025.116949
oa: '1'
publication: Solid State Ionics
publication_identifier:
issn:
- 0167-2738
publication_status: published
publisher: Elsevier BV
quality_controlled: '1'
status: public
title: Demonstration of domain wall current in MgO-doped lithium niobate single crystals
up to 400°C
type: journal_article
user_id: '22501'
volume: 429
year: '2025'
...
---
_id: '61337'
abstract:
- lang: eng
text: Lithium niobate–tantalate mixed (LNT) crystals promise improved performance
and new applications for optical, piezomechanical, or electrical devices when
compared to the end composition compounds lithium niobate and lithium tantalate.
The macroscopic properties of ferroelectrics highly depend on the structure of
the underlying ferroelectric domains, which within mixed crystals can interact
with the local changes in chemical compositions. In this work, we demonstrate
how ferroelectric domain walls can unambiguously be identified and distinguished
from local changes in composition by correlating piezoresponse force microscopy
with second harmonic generation microscopy, using the Cherenkov contrast, reference
crystal contrast, and negative phase mismatching contrast. We demonstrate how
measuring the associated intensity change when approaching negative phase mismatching
can be used to deduce the local tantalum concentration fast and over a large sample
area. Based on these results, we study the natural domain structures that appear
from Czochralski-grown, multi-domain LNT solid solution crystals. The developed
results and methods serve as the central foundation to poling these mixed crystal
systems and are key for their integration and applications.
article_number: '034101'
author:
- first_name: Boris
full_name: Koppitz, Boris
last_name: Koppitz
- first_name: Tanya
full_name: Saxena, Tanya
last_name: Saxena
- first_name: Felix
full_name: Bernhardt, Felix
last_name: Bernhardt
- first_name: Steffen
full_name: Ganschow, Steffen
last_name: Ganschow
- first_name: Simone
full_name: Sanna, Simone
last_name: Sanna
- first_name: Michael
full_name: Rüsing, Michael
id: '22501'
last_name: Rüsing
orcid: 0000-0003-4682-4577
- first_name: Lukas M.
full_name: Eng, Lukas M.
last_name: Eng
citation:
ama: Koppitz B, Saxena T, Bernhardt F, et al. Second harmonic generation contrasts
of ferroelectric domain structures and composition in lithium niobate–tantalate
mixed crystals. Journal of Applied Physics. 2025;138(3). doi:10.1063/5.0276183
apa: Koppitz, B., Saxena, T., Bernhardt, F., Ganschow, S., Sanna, S., Rüsing, M.,
& Eng, L. M. (2025). Second harmonic generation contrasts of ferroelectric
domain structures and composition in lithium niobate–tantalate mixed crystals.
Journal of Applied Physics, 138(3), Article 034101. https://doi.org/10.1063/5.0276183
bibtex: '@article{Koppitz_Saxena_Bernhardt_Ganschow_Sanna_Rüsing_Eng_2025, title={Second
harmonic generation contrasts of ferroelectric domain structures and composition
in lithium niobate–tantalate mixed crystals}, volume={138}, DOI={10.1063/5.0276183},
number={3034101}, journal={Journal of Applied Physics}, publisher={AIP Publishing},
author={Koppitz, Boris and Saxena, Tanya and Bernhardt, Felix and Ganschow, Steffen
and Sanna, Simone and Rüsing, Michael and Eng, Lukas M.}, year={2025} }'
chicago: Koppitz, Boris, Tanya Saxena, Felix Bernhardt, Steffen Ganschow, Simone
Sanna, Michael Rüsing, and Lukas M. Eng. “Second Harmonic Generation Contrasts
of Ferroelectric Domain Structures and Composition in Lithium Niobate–Tantalate
Mixed Crystals.” Journal of Applied Physics 138, no. 3 (2025). https://doi.org/10.1063/5.0276183.
ieee: 'B. Koppitz et al., “Second harmonic generation contrasts of ferroelectric
domain structures and composition in lithium niobate–tantalate mixed crystals,”
Journal of Applied Physics, vol. 138, no. 3, Art. no. 034101, 2025, doi:
10.1063/5.0276183.'
mla: Koppitz, Boris, et al. “Second Harmonic Generation Contrasts of Ferroelectric
Domain Structures and Composition in Lithium Niobate–Tantalate Mixed Crystals.”
Journal of Applied Physics, vol. 138, no. 3, 034101, AIP Publishing, 2025,
doi:10.1063/5.0276183.
short: B. Koppitz, T. Saxena, F. Bernhardt, S. Ganschow, S. Sanna, M. Rüsing, L.M.
Eng, Journal of Applied Physics 138 (2025).
date_created: 2025-09-17T16:16:04Z
date_updated: 2025-09-17T16:18:02Z
department:
- _id: '15'
- _id: '623'
doi: 10.1063/5.0276183
funded_apc: '1'
intvolume: ' 138'
issue: '3'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://pubs.aip.org/aip/jap/article/138/3/034101/3352909
oa: '1'
publication: Journal of Applied Physics
publication_identifier:
issn:
- 0021-8979
- 1089-7550
publication_status: published
publisher: AIP Publishing
quality_controlled: '1'
status: public
title: Second harmonic generation contrasts of ferroelectric domain structures and
composition in lithium niobate–tantalate mixed crystals
type: journal_article
user_id: '22501'
volume: 138
year: '2025'
...
---
_id: '58519'
abstract:
- lang: eng
text: A unified theoretical approach to describe the properties of multimode
squeezed light generated in a lossy medium is presented. This approach is valid
for Markovian environments and includes both a model of discrete losses based
on the beamsplitter approach and a generalized continuous loss model based on
the spatial Langevin equation. For an important class of Gaussian states, we derive
master equations for the second-order correlation functions and illustrate their
solution for both frequency-independent and frequency-dependent losses. Studying
the mode structure, we demonstrate that in a lossy environment no broadband basis
without quadrature correlations between the different broadband modes exists.
Therefore, various techniques and strategies to introduce broadband modes can
be considered. We show that the Mercer expansion and the Williamson-Euler decomposition
do not provide modes in which the maximal squeezing contained in the system can
be measured. In turn, we find a new broadband basis that maximizes squeezing in
the lossy system and present an algorithm to construct it.
article_number: '1621'
author:
- first_name: Denis A.
full_name: Kopylov, Denis A.
last_name: Kopylov
- first_name: Torsten
full_name: Meier, Torsten
id: '344'
last_name: Meier
orcid: 0000-0001-8864-2072
- first_name: Polina R.
full_name: Sharapova, Polina R.
id: '60286'
last_name: Sharapova
citation:
ama: Kopylov DA, Meier T, Sharapova PR. Theory of Multimode Squeezed Light Generation
in Lossy Media. Quantum. 2025;9. doi:10.22331/q-2025-02-04-1621
apa: Kopylov, D. A., Meier, T., & Sharapova, P. R. (2025). Theory of Multimode
Squeezed Light Generation in Lossy Media. Quantum, 9, Article 1621.
https://doi.org/10.22331/q-2025-02-04-1621
bibtex: '@article{Kopylov_Meier_Sharapova_2025, title={Theory of Multimode Squeezed
Light Generation in Lossy Media}, volume={9}, DOI={10.22331/q-2025-02-04-1621},
number={1621}, journal={Quantum}, publisher={Verein zur Forderung des Open Access
Publizierens in den Quantenwissenschaften}, author={Kopylov, Denis A. and Meier,
Torsten and Sharapova, Polina R.}, year={2025} }'
chicago: Kopylov, Denis A., Torsten Meier, and Polina R. Sharapova. “Theory of Multimode
Squeezed Light Generation in Lossy Media.” Quantum 9 (2025). https://doi.org/10.22331/q-2025-02-04-1621.
ieee: 'D. A. Kopylov, T. Meier, and P. R. Sharapova, “Theory of Multimode Squeezed
Light Generation in Lossy Media,” Quantum, vol. 9, Art. no. 1621, 2025,
doi: 10.22331/q-2025-02-04-1621.'
mla: Kopylov, Denis A., et al. “Theory of Multimode Squeezed Light Generation in
Lossy Media.” Quantum, vol. 9, 1621, Verein zur Forderung des Open Access
Publizierens in den Quantenwissenschaften, 2025, doi:10.22331/q-2025-02-04-1621.
short: D.A. Kopylov, T. Meier, P.R. Sharapova, Quantum 9 (2025).
date_created: 2025-02-05T12:57:37Z
date_updated: 2025-09-18T13:22:26Z
department:
- _id: '15'
- _id: '569'
- _id: '170'
- _id: '293'
- _id: '35'
- _id: '230'
- _id: '623'
- _id: '27'
doi: 10.22331/q-2025-02-04-1621
intvolume: ' 9'
language:
- iso: eng
project:
- _id: '266'
name: 'PhoQC: PhoQC: Photonisches Quantencomputing'
- _id: '52'
name: Computing Resources Provided by the Paderborn Center for Parallel Computing
publication: Quantum
publication_identifier:
issn:
- 2521-327X
publication_status: published
publisher: Verein zur Forderung des Open Access Publizierens in den Quantenwissenschaften
status: public
title: Theory of Multimode Squeezed Light Generation in Lossy Media
type: journal_article
user_id: '16199'
volume: 9
year: '2025'
...
---
_id: '60891'
abstract:
- lang: eng
text: Straight dielectric waveguide channels made from slabs of thin-film lithium
niobate (TFLN), or lithium niobate on insulator (LNOI), are investigated in the
linear regime, for channels of rib and strip type with common trapezoidal cross
sections, in Z-cut and X-cut samples at varying on-chip orientation. We clarify
the theoretical basis for the waveguides with potentially non-diagonal core permittivity.
Symmetry classes can be distinguished that differ in their consequences for potential
modal degeneracy and polarization conversion. Our rigorous numerical analysis
by means of a finite-element solver takes the anisotropy of the lithium niobate
cores rigorously into account. We discuss extensive data for effective indices,
polarization properties, and hybridization of guided modes, in single- and multimode
channels. Scans over the waveguide width and orientation as primary parameters
are complemented by a series of illustrations of vectorial mode profiles. These
turn out to be essentially complex in cases of X-cut channels at non-crystal-axis-aligned
orientations.
author:
- first_name: Manfred
full_name: Hammer, Manfred
id: '48077'
last_name: Hammer
orcid: 0000-0002-6331-9348
- first_name: Shahriar
full_name: Khan, Shahriar
last_name: Khan
- first_name: Behnood
full_name: Taheri, Behnood
last_name: Taheri
- first_name: Henna
full_name: Farheen, Henna
id: '53444'
last_name: Farheen
orcid: 0000-0001-7730-3489
- first_name: Jens
full_name: Förstner, Jens
id: '158'
last_name: Förstner
orcid: 0000-0001-7059-9862
citation:
ama: 'Hammer M, Khan S, Taheri B, Farheen H, Förstner J. TFLN channel waveguides
of rib and strip type: Properties of guided modes. Optics Continuum. 2025;4(10):2356.
doi:10.1364/optcon.569959'
apa: 'Hammer, M., Khan, S., Taheri, B., Farheen, H., & Förstner, J. (2025).
TFLN channel waveguides of rib and strip type: Properties of guided modes. Optics
Continuum, 4(10), 2356. https://doi.org/10.1364/optcon.569959'
bibtex: '@article{Hammer_Khan_Taheri_Farheen_Förstner_2025, title={TFLN channel
waveguides of rib and strip type: Properties of guided modes}, volume={4}, DOI={10.1364/optcon.569959}, number={10},
journal={Optics Continuum}, publisher={Optica Publishing Group}, author={Hammer,
Manfred and Khan, Shahriar and Taheri, Behnood and Farheen, Henna and Förstner,
Jens}, year={2025}, pages={2356} }'
chicago: 'Hammer, Manfred, Shahriar Khan, Behnood Taheri, Henna Farheen, and Jens
Förstner. “TFLN Channel Waveguides of Rib and Strip Type: Properties of Guided
Modes.” Optics Continuum 4, no. 10 (2025): 2356. https://doi.org/10.1364/optcon.569959.'
ieee: 'M. Hammer, S. Khan, B. Taheri, H. Farheen, and J. Förstner, “TFLN channel
waveguides of rib and strip type: Properties of guided modes,” Optics Continuum,
vol. 4, no. 10, p. 2356, 2025, doi: 10.1364/optcon.569959.'
mla: 'Hammer, Manfred, et al. “TFLN Channel Waveguides of Rib and Strip Type: Properties
of Guided Modes.” Optics Continuum, vol. 4, no. 10, Optica Publishing Group,
2025, p. 2356, doi:10.1364/optcon.569959.'
short: M. Hammer, S. Khan, B. Taheri, H. Farheen, J. Förstner, Optics Continuum
4 (2025) 2356.
date_created: 2025-08-06T09:36:30Z
date_updated: 2025-10-05T11:52:55Z
ddc:
- '530'
department:
- _id: '61'
- _id: '230'
- _id: '429'
- _id: '623'
doi: 10.1364/optcon.569959
file:
- access_level: closed
content_type: application/pdf
creator: fossie
date_created: 2025-10-05T11:48:25Z
date_updated: 2025-10-05T11:48:25Z
file_id: '61516'
file_name: 2025-08 Hammer - Optics Continuum - TFLN channel waveguides of rib and
strip type. Properties of guided modes (official version).pdf
file_size: 5417636
relation: main_file
success: 1
file_date_updated: 2025-10-05T11:48:25Z
has_accepted_license: '1'
intvolume: ' 4'
issue: '10'
keyword:
- tet_topic_waveguide
language:
- iso: eng
page: '2356'
publication: Optics Continuum
publication_identifier:
issn:
- 2770-0208
publication_status: published
publisher: Optica Publishing Group
status: public
title: 'TFLN channel waveguides of rib and strip type: Properties of guided modes'
type: journal_article
user_id: '158'
volume: 4
year: '2025'
...
---
_id: '61760'
abstract:
- lang: eng
text: We present a topology-optimized silicon nitride (Si3N4) coupler designed to
enhance the coupling efficiency between integrated single-photon emitters and
photonic waveguide modes. By leveraging inverse design techniques, we optimize
the coupler’s geometry to maximize power transfer while maintaining fabrication
feasibility by improving mode overlap and directional emission, addressing the
challenge of low coupling efficiency caused by size mismatch and material incompatibility.
Simulations demonstrate a substantial enhancement in photon extraction and waveguide
coupling. This approach can be extended to other photonic devices, offering a
versatile framework for improving quantum light-matter interactions in integrated
photonics.
author:
- first_name: Henna
full_name: Farheen, Henna
id: '53444'
last_name: Farheen
orcid: 0000-0001-7730-3489
- first_name: Yuheng
full_name: Chen, Yuheng
last_name: Chen
- first_name: Peigang
full_name: Chen, Peigang
last_name: Chen
- first_name: Artem
full_name: Kryvobok, Artem
last_name: Kryvobok
- first_name: Samuel
full_name: Peana, Samuel
last_name: Peana
- first_name: Alexander
full_name: Senichev, Alexander
last_name: Senichev
- first_name: Vladimir M.
full_name: Shalaev, Vladimir M.
last_name: Shalaev
- first_name: Alexandra
full_name: Boltasseva, Alexandra
last_name: Boltasseva
- first_name: Jens
full_name: Förstner, Jens
id: '158'
last_name: Förstner
orcid: 0000-0001-7059-9862
- first_name: Alexander V.
full_name: Kildishev, Alexander V.
last_name: Kildishev
citation:
ama: 'Farheen H, Chen Y, Chen P, et al. Topology-optimized silicon nitride coupler
for integrated single-photon emitters. In: Ni X, Cai W, eds. Photonic Computing:
From Materials and Devices to Systems and Applications II. SPIE; 2025. doi:10.1117/12.3065734'
apa: 'Farheen, H., Chen, Y., Chen, P., Kryvobok, A., Peana, S., Senichev, A., Shalaev,
V. M., Boltasseva, A., Förstner, J., & Kildishev, A. V. (2025). Topology-optimized
silicon nitride coupler for integrated single-photon emitters. In X. Ni &
W. Cai (Eds.), Photonic Computing: From Materials and Devices to Systems and
Applications II. SPIE. https://doi.org/10.1117/12.3065734'
bibtex: '@inproceedings{Farheen_Chen_Chen_Kryvobok_Peana_Senichev_Shalaev_Boltasseva_Förstner_Kildishev_2025,
title={Topology-optimized silicon nitride coupler for integrated single-photon
emitters}, DOI={10.1117/12.3065734},
booktitle={Photonic Computing: From Materials and Devices to Systems and Applications
II}, publisher={SPIE}, author={Farheen, Henna and Chen, Yuheng and Chen, Peigang
and Kryvobok, Artem and Peana, Samuel and Senichev, Alexander and Shalaev, Vladimir
M. and Boltasseva, Alexandra and Förstner, Jens and Kildishev, Alexander V.},
editor={Ni, Xingjie and Cai, Wenshan}, year={2025} }'
chicago: 'Farheen, Henna, Yuheng Chen, Peigang Chen, Artem Kryvobok, Samuel Peana,
Alexander Senichev, Vladimir M. Shalaev, Alexandra Boltasseva, Jens Förstner,
and Alexander V. Kildishev. “Topology-Optimized Silicon Nitride Coupler for Integrated
Single-Photon Emitters.” In Photonic Computing: From Materials and Devices
to Systems and Applications II, edited by Xingjie Ni and Wenshan Cai. SPIE,
2025. https://doi.org/10.1117/12.3065734.'
ieee: 'H. Farheen et al., “Topology-optimized silicon nitride coupler for
integrated single-photon emitters,” in Photonic Computing: From Materials and
Devices to Systems and Applications II, 2025, doi: 10.1117/12.3065734.'
mla: 'Farheen, Henna, et al. “Topology-Optimized Silicon Nitride Coupler for Integrated
Single-Photon Emitters.” Photonic Computing: From Materials and Devices to
Systems and Applications II, edited by Xingjie Ni and Wenshan Cai, SPIE, 2025,
doi:10.1117/12.3065734.'
short: 'H. Farheen, Y. Chen, P. Chen, A. Kryvobok, S. Peana, A. Senichev, V.M. Shalaev,
A. Boltasseva, J. Förstner, A.V. Kildishev, in: X. Ni, W. Cai (Eds.), Photonic
Computing: From Materials and Devices to Systems and Applications II, SPIE, 2025.'
date_created: 2025-10-08T15:20:13Z
date_updated: 2025-10-08T15:22:30Z
department:
- _id: '61'
- _id: '230'
- _id: '429'
- _id: '623'
doi: 10.1117/12.3065734
editor:
- first_name: Xingjie
full_name: Ni, Xingjie
last_name: Ni
- first_name: Wenshan
full_name: Cai, Wenshan
last_name: Cai
keyword:
- tet_topic_waveguide
language:
- iso: eng
publication: 'Photonic Computing: From Materials and Devices to Systems and Applications
II'
publication_status: published
publisher: SPIE
status: public
title: Topology-optimized silicon nitride coupler for integrated single-photon emitters
type: conference
user_id: '158'
year: '2025'
...
---
_id: '62286'
abstract:
- lang: eng
text: Optical tweezer arrays of laser-cooled and individually controlled particles
have revolutionized atomic, molecular, and optical physics. They afford exquisite
capabilities for applications in quantum simulation of many-body physics, quantum
computation, and sensing. Underlying this development is the technical maturity
of generating scalable optical beams, enabled by active components and a high
numerical aperture objective. However, such a complex combination of bulk optics
outside the vacuum chamber is very sensitive to any vibration and drift. Here,
we demonstrate the generation of a 3 × 3 static tweezer array with a single chip-scale
multifunctional metasurface element in vacuum, replacing the meter-long free space
optics. Fluorescence counts on the camera validate the successful trapping of
the atomic ensemble array and showcase a promising strategy for integrated photonics
with cold atom systems. The introduction of a polarization independent dual-wavelength
metasurface significantly enhances fluorescence collection efficiency while reducing
experimental complexity. This approach paves the way for scalable neutral atom
platforms and offers a compelling route towards the realization of next generation
quantum metasurfaces.
article_number: '51085'
article_type: original
author:
- first_name: Donghao
full_name: Li, Donghao
last_name: Li
- first_name: Qiming
full_name: Liao, Qiming
last_name: Liao
- first_name: Beining
full_name: Xu, Beining
last_name: Xu
- first_name: Thomas
full_name: Zentgraf, Thomas
id: '30525'
last_name: Zentgraf
orcid: 0000-0002-8662-1101
- first_name: Emmanuel
full_name: Narvaez Castaneda, Emmanuel
last_name: Narvaez Castaneda
- first_name: Yaoting
full_name: Zhou, Yaoting
last_name: Zhou
- first_name: Keyu
full_name: Qin, Keyu
last_name: Qin
- first_name: Zhongxiao
full_name: Xu, Zhongxiao
last_name: Xu
- first_name: Heng
full_name: Shen, Heng
last_name: Shen
- first_name: Lingling
full_name: Huang, Lingling
last_name: Huang
citation:
ama: Li D, Liao Q, Xu B, et al. In vacuum metasurface for optical microtrap array.
Optics Express. 2025;33(24). doi:10.1364/oe.580201
apa: Li, D., Liao, Q., Xu, B., Zentgraf, T., Narvaez Castaneda, E., Zhou, Y., Qin,
K., Xu, Z., Shen, H., & Huang, L. (2025). In vacuum metasurface for optical
microtrap array. Optics Express, 33(24), Article 51085. https://doi.org/10.1364/oe.580201
bibtex: '@article{Li_Liao_Xu_Zentgraf_Narvaez Castaneda_Zhou_Qin_Xu_Shen_Huang_2025,
title={In vacuum metasurface for optical microtrap array}, volume={33}, DOI={10.1364/oe.580201}, number={2451085},
journal={Optics Express}, publisher={Optica Publishing Group}, author={Li, Donghao
and Liao, Qiming and Xu, Beining and Zentgraf, Thomas and Narvaez Castaneda, Emmanuel
and Zhou, Yaoting and Qin, Keyu and Xu, Zhongxiao and Shen, Heng and Huang, Lingling},
year={2025} }'
chicago: Li, Donghao, Qiming Liao, Beining Xu, Thomas Zentgraf, Emmanuel Narvaez
Castaneda, Yaoting Zhou, Keyu Qin, Zhongxiao Xu, Heng Shen, and Lingling Huang.
“In Vacuum Metasurface for Optical Microtrap Array.” Optics Express 33,
no. 24 (2025). https://doi.org/10.1364/oe.580201.
ieee: 'D. Li et al., “In vacuum metasurface for optical microtrap array,”
Optics Express, vol. 33, no. 24, Art. no. 51085, 2025, doi: 10.1364/oe.580201.'
mla: Li, Donghao, et al. “In Vacuum Metasurface for Optical Microtrap Array.” Optics
Express, vol. 33, no. 24, 51085, Optica Publishing Group, 2025, doi:10.1364/oe.580201.
short: D. Li, Q. Liao, B. Xu, T. Zentgraf, E. Narvaez Castaneda, Y. Zhou, K. Qin,
Z. Xu, H. Shen, L. Huang, Optics Express 33 (2025).
date_created: 2025-11-24T06:31:17Z
date_updated: 2025-11-24T06:35:19Z
department:
- _id: '15'
- _id: '230'
- _id: '289'
- _id: '623'
doi: 10.1364/oe.580201
intvolume: ' 33'
issue: '24'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://opg.optica.org/oe/fulltext.cfm?uri=oe-33-24-51085
oa: '1'
publication: Optics Express
publication_identifier:
issn:
- 1094-4087
publication_status: published
publisher: Optica Publishing Group
quality_controlled: '1'
status: public
title: In vacuum metasurface for optical microtrap array
type: journal_article
user_id: '30525'
volume: 33
year: '2025'
...
---
_id: '62639'
author:
- first_name: Stephan
full_name: Kruse, Stephan
id: '38254'
last_name: Kruse
- first_name: Christine
full_name: Silberhorn, Christine
id: '26263'
last_name: Silberhorn
- first_name: Benjamin
full_name: Brecht, Benjamin
id: '27150'
last_name: Brecht
orcid: '0000-0003-4140-0556 '
- first_name: Tobias
full_name: Schwabe, Tobias
id: '39217'
last_name: Schwabe
citation:
ama: Kruse S, Silberhorn C, Brecht B, Schwabe T. Optisch basierter Digital-Analog-Umsetzer.
Published online 2025.
apa: Kruse, S., Silberhorn, C., Brecht, B., & Schwabe, T. (2025). Optisch
basierter Digital-Analog-Umsetzer.
bibtex: '@article{Kruse_Silberhorn_Brecht_Schwabe_2025, title={Optisch basierter
Digital-Analog-Umsetzer}, author={Kruse, Stephan and Silberhorn, Christine and
Brecht, Benjamin and Schwabe, Tobias}, year={2025} }'
chicago: Kruse, Stephan, Christine Silberhorn, Benjamin Brecht, and Tobias Schwabe.
“Optisch Basierter Digital-Analog-Umsetzer,” 2025.
ieee: S. Kruse, C. Silberhorn, B. Brecht, and T. Schwabe, “Optisch basierter Digital-Analog-Umsetzer.”
2025.
mla: Kruse, Stephan, et al. Optisch Basierter Digital-Analog-Umsetzer. 2025.
short: S. Kruse, C. Silberhorn, B. Brecht, T. Schwabe, (2025).
date_created: 2025-11-27T07:00:50Z
date_updated: 2025-11-27T07:07:16Z
department:
- _id: '58'
- _id: '623'
- _id: '288'
ipc: H03M 1/66
ipn: DE102023212604B3
publication_date: 2025-01-23
status: public
title: Optisch basierter Digital-Analog-Umsetzer
type: patent
user_id: '38254'
year: '2025'
...
---
_id: '62749'
abstract:
- lang: eng
text: "Coherent Raman scattering techniques as coherent anti-Stokes Raman scattering
(CARS), offer significant advantages in terms of pixel dwell times and speed as
compared to spontaneous Raman scattering for investigations of crystalline materials.
However, the spectral information in CARS is often hampered by the presence of
a nonresonant contribution to the scattering process that shifts and distorts
the Raman peaks. In this work, we apply a method to obtain nonresonant background-free
spectra based on time-delayed, broadband CARS (TD-BCARS) using an intrapulse excitation
scheme. In particular, this method can measure the phononic dephasing times across
the full phonon spectrum at once. We test the methodology on amorphous SiO2 (glass),
which is used to characterize the setup-specific and material-independent response
times, and then apply TD-BCARS to the analysis of single crystals of diamond and
ferroelectrics of potassium titanyl phosphate (KTP) and potassium titanyl arsenate
(KTA). For diamond, we determine a dephasing time of \U0001D70F=7.81 ps for the
single \U0001D460\U0001D45D3 peak."
article_number: '224106'
article_type: original
author:
- first_name: F.
full_name: Hempel, F.
last_name: Hempel
- first_name: Michael
full_name: Rüsing, Michael
id: '22501'
last_name: Rüsing
orcid: 0000-0003-4682-4577
- first_name: F.
full_name: Vernuccio, F.
last_name: Vernuccio
- first_name: K. J.
full_name: Spychala, K. J.
last_name: Spychala
- first_name: R.
full_name: Buschbeck, R.
last_name: Buschbeck
- first_name: G.
full_name: Cerullo, G.
last_name: Cerullo
- first_name: D.
full_name: Polli, D.
last_name: Polli
- first_name: L. M.
full_name: Eng, L. M.
last_name: Eng
citation:
ama: Hempel F, Rüsing M, Vernuccio F, et al. Phonon dephasing times determined with
time-delayed broadband coherent anti-Stokes Raman scattering. Physical Review
B. 2025;112(22). doi:10.1103/1ctr-csjy
apa: Hempel, F., Rüsing, M., Vernuccio, F., Spychala, K. J., Buschbeck, R., Cerullo,
G., Polli, D., & Eng, L. M. (2025). Phonon dephasing times determined with
time-delayed broadband coherent anti-Stokes Raman scattering. Physical Review
B, 112(22), Article 224106. https://doi.org/10.1103/1ctr-csjy
bibtex: '@article{Hempel_Rüsing_Vernuccio_Spychala_Buschbeck_Cerullo_Polli_Eng_2025,
title={Phonon dephasing times determined with time-delayed broadband coherent
anti-Stokes Raman scattering}, volume={112}, DOI={10.1103/1ctr-csjy},
number={22224106}, journal={Physical Review B}, publisher={American Physical Society
(APS)}, author={Hempel, F. and Rüsing, Michael and Vernuccio, F. and Spychala,
K. J. and Buschbeck, R. and Cerullo, G. and Polli, D. and Eng, L. M.}, year={2025}
}'
chicago: Hempel, F., Michael Rüsing, F. Vernuccio, K. J. Spychala, R. Buschbeck,
G. Cerullo, D. Polli, and L. M. Eng. “Phonon Dephasing Times Determined with Time-Delayed
Broadband Coherent Anti-Stokes Raman Scattering.” Physical Review B 112,
no. 22 (2025). https://doi.org/10.1103/1ctr-csjy.
ieee: 'F. Hempel et al., “Phonon dephasing times determined with time-delayed
broadband coherent anti-Stokes Raman scattering,” Physical Review B, vol.
112, no. 22, Art. no. 224106, 2025, doi: 10.1103/1ctr-csjy.'
mla: Hempel, F., et al. “Phonon Dephasing Times Determined with Time-Delayed Broadband
Coherent Anti-Stokes Raman Scattering.” Physical Review B, vol. 112, no.
22, 224106, American Physical Society (APS), 2025, doi:10.1103/1ctr-csjy.
short: F. Hempel, M. Rüsing, F. Vernuccio, K.J. Spychala, R. Buschbeck, G. Cerullo,
D. Polli, L.M. Eng, Physical Review B 112 (2025).
date_created: 2025-12-02T19:21:33Z
date_updated: 2025-12-02T19:23:55Z
department:
- _id: '15'
- _id: '623'
- _id: '288'
doi: 10.1103/1ctr-csjy
external_id:
arxiv:
- '2506.05519'
intvolume: ' 112'
issue: '22'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2506.05519
oa: '1'
publication: Physical Review B
publication_identifier:
issn:
- 2469-9950
- 2469-9969
publication_status: published
publisher: American Physical Society (APS)
quality_controlled: '1'
status: public
title: Phonon dephasing times determined with time-delayed broadband coherent anti-Stokes
Raman scattering
type: journal_article
user_id: '22501'
volume: 112
year: '2025'
...
---
_id: '62860'
abstract:
- lang: eng
text: "\r\n The Quantum Internet, a network of quantum-enabled
infrastructure, represents the next frontier in telecommunications, promising
capabilities that cannot be attained by classical counterparts. A crucial step
in realizing such large-scale quantum networks is the integration of entanglement
distribution within existing telecommunication infrastructure. Here, we demonstrate
a real-world scalable quantum networking testbed deployed within Deutsche Telekom’s
metropolitan fibers in Berlin. Using commercially available quantum devices and
standard add-drop multiplexing hardware, we distributed polarization-entangled
photon pairs over dynamically selectable looped fiber paths ranging from 10 m
to 60 km and showed entanglement distribution over up to approximately 100 km.
Quantum signals, transmitted at 1324 nm (O-band), coexist with conventional bidirectional
C-band traffic without dedicated fibers or infrastructure changes. Active stabilization
of the polarization enables robust long-term performance, achieving entanglement
Bell-state fidelity bounds between 85% and 99% and Clauser–Horne–Shimony–Holt
parameter\r\n S\r\n -values
between 2.36 and 2.74 during continuous multiday operation. By achieving a high-fidelity
entanglement distribution with less than 1.5% downtime, we confirm the feasibility
of hybrid quantum-classical networks under real-world conditions at the metropolitan
scale. These results establish deployment benchmarks and provide a practical roadmap
for telecom operators to integrate quantum capabilities.\r\n "
article_number: '1072'
author:
- first_name: Matheus
full_name: Sena, Matheus
last_name: Sena
- first_name: Mael
full_name: Flament, Mael
last_name: Flament
- first_name: Shane
full_name: Andrewski, Shane
last_name: Andrewski
- first_name: Ioannis
full_name: Caltzidis, Ioannis
last_name: Caltzidis
- first_name: Niccolò
full_name: Bigagli, Niccolò
last_name: Bigagli
- first_name: Thomas
full_name: Rieser, Thomas
last_name: Rieser
- first_name: Gabriel
full_name: Bello Portmann, Gabriel
last_name: Bello Portmann
- first_name: Rourke
full_name: Sekelsky, Rourke
last_name: Sekelsky
- first_name: Ralf-Peter
full_name: Braun, Ralf-Peter
last_name: Braun
- first_name: Alexander N.
full_name: Craddock, Alexander N.
last_name: Craddock
- first_name: Maximilian
full_name: Schulz, Maximilian
last_name: Schulz
- first_name: Klaus
full_name: Jöns, Klaus
id: '85353'
last_name: Jöns
- first_name: Michaela
full_name: Ritter, Michaela
last_name: Ritter
- first_name: Marc
full_name: Geitz, Marc
last_name: Geitz
- first_name: Oliver
full_name: Holschke, Oliver
last_name: Holschke
- first_name: Mehdi
full_name: Namazi, Mehdi
last_name: Namazi
citation:
ama: Sena M, Flament M, Andrewski S, et al. High-fidelity quantum entanglement distribution
in metropolitan fiber networks with co-propagating classical traffic. Journal
of Optical Communications and Networking. 2025;17(12). doi:10.1364/jocn.575396
apa: Sena, M., Flament, M., Andrewski, S., Caltzidis, I., Bigagli, N., Rieser, T.,
Bello Portmann, G., Sekelsky, R., Braun, R.-P., Craddock, A. N., Schulz, M., Jöns,
K., Ritter, M., Geitz, M., Holschke, O., & Namazi, M. (2025). High-fidelity
quantum entanglement distribution in metropolitan fiber networks with co-propagating
classical traffic. Journal of Optical Communications and Networking, 17(12),
Article 1072. https://doi.org/10.1364/jocn.575396
bibtex: '@article{Sena_Flament_Andrewski_Caltzidis_Bigagli_Rieser_Bello Portmann_Sekelsky_Braun_Craddock_et
al._2025, title={High-fidelity quantum entanglement distribution in metropolitan
fiber networks with co-propagating classical traffic}, volume={17}, DOI={10.1364/jocn.575396},
number={121072}, journal={Journal of Optical Communications and Networking}, publisher={Optica
Publishing Group}, author={Sena, Matheus and Flament, Mael and Andrewski, Shane
and Caltzidis, Ioannis and Bigagli, Niccolò and Rieser, Thomas and Bello Portmann,
Gabriel and Sekelsky, Rourke and Braun, Ralf-Peter and Craddock, Alexander N.
and et al.}, year={2025} }'
chicago: Sena, Matheus, Mael Flament, Shane Andrewski, Ioannis Caltzidis, Niccolò
Bigagli, Thomas Rieser, Gabriel Bello Portmann, et al. “High-Fidelity Quantum
Entanglement Distribution in Metropolitan Fiber Networks with Co-Propagating Classical
Traffic.” Journal of Optical Communications and Networking 17, no. 12 (2025).
https://doi.org/10.1364/jocn.575396.
ieee: 'M. Sena et al., “High-fidelity quantum entanglement distribution in
metropolitan fiber networks with co-propagating classical traffic,” Journal
of Optical Communications and Networking, vol. 17, no. 12, Art. no. 1072,
2025, doi: 10.1364/jocn.575396.'
mla: Sena, Matheus, et al. “High-Fidelity Quantum Entanglement Distribution in Metropolitan
Fiber Networks with Co-Propagating Classical Traffic.” Journal of Optical Communications
and Networking, vol. 17, no. 12, 1072, Optica Publishing Group, 2025, doi:10.1364/jocn.575396.
short: M. Sena, M. Flament, S. Andrewski, I. Caltzidis, N. Bigagli, T. Rieser, G.
Bello Portmann, R. Sekelsky, R.-P. Braun, A.N. Craddock, M. Schulz, K. Jöns, M.
Ritter, M. Geitz, O. Holschke, M. Namazi, Journal of Optical Communications and
Networking 17 (2025).
date_created: 2025-12-04T12:20:01Z
date_updated: 2025-12-04T13:37:02Z
department:
- _id: '623'
- _id: '15'
doi: 10.1364/jocn.575396
intvolume: ' 17'
issue: '12'
language:
- iso: eng
publication: Journal of Optical Communications and Networking
publication_identifier:
issn:
- 1943-0620
- 1943-0639
publication_status: published
publisher: Optica Publishing Group
status: public
title: High-fidelity quantum entanglement distribution in metropolitan fiber networks
with co-propagating classical traffic
type: journal_article
user_id: '85353'
volume: 17
year: '2025'
...
---
_id: '62911'
abstract:
- lang: eng
text: In this paper, we theoretically study the spectral and temporal properties
of pulsed spontaneous parametric down-conversion (SPDC) generated in lossy waveguides.
Our theoretical approach is based on the formalism of Gaussian states and the
Langevin equation, which is elaborated for weak parametric down-conversion and
photon-number-unresolved click detection. Using the example of frequency-degenerate
type-II SPDC generated under the pump-idler group-velocity-matching condition,
we show how the joint-spectral intensity, mode structure, normalized second-order
correlation function, and Hong-Ou-Mandel interference pattern depend on internal
losses of the SPDC process. We found that the joint-spectral intensity is almost
insensitive to internal losses, while the second-order correlation function shows
a strong dependence on them, being different for the signal and idler beams in
the presence of internal losses. Based on the sensitivity of the normalized second-order
correlation function, we show how its measurement can be used to experimentally
determine internal losses.
article_number: '033122'
author:
- first_name: Denis A.
full_name: Kopylov, Denis A.
last_name: Kopylov
- first_name: Michael
full_name: Stefszky, Michael
id: '42777'
last_name: Stefszky
- first_name: Torsten
full_name: Meier, Torsten
id: '344'
last_name: Meier
orcid: 0000-0001-8864-2072
- first_name: Christine
full_name: Silberhorn, Christine
id: '26263'
last_name: Silberhorn
- first_name: Polina R.
full_name: Sharapova, Polina R.
id: '60286'
last_name: Sharapova
citation:
ama: 'Kopylov DA, Stefszky M, Meier T, Silberhorn C, Sharapova PR. Spectral and
temporal properties of type-II parametric down-conversion: The impact of losses
during state generation. Physical Review Research. 2025;7(3). doi:10.1103/zp72-7qwl'
apa: 'Kopylov, D. A., Stefszky, M., Meier, T., Silberhorn, C., & Sharapova,
P. R. (2025). Spectral and temporal properties of type-II parametric down-conversion:
The impact of losses during state generation. Physical Review Research,
7(3), Article 033122. https://doi.org/10.1103/zp72-7qwl'
bibtex: '@article{Kopylov_Stefszky_Meier_Silberhorn_Sharapova_2025, title={Spectral
and temporal properties of type-II parametric down-conversion: The impact of losses
during state generation}, volume={7}, DOI={10.1103/zp72-7qwl},
number={3033122}, journal={Physical Review Research}, publisher={American Physical
Society (APS)}, author={Kopylov, Denis A. and Stefszky, Michael and Meier, Torsten
and Silberhorn, Christine and Sharapova, Polina R.}, year={2025} }'
chicago: 'Kopylov, Denis A., Michael Stefszky, Torsten Meier, Christine Silberhorn,
and Polina R. Sharapova. “Spectral and Temporal Properties of Type-II Parametric
down-Conversion: The Impact of Losses during State Generation.” Physical Review
Research 7, no. 3 (2025). https://doi.org/10.1103/zp72-7qwl.'
ieee: 'D. A. Kopylov, M. Stefszky, T. Meier, C. Silberhorn, and P. R. Sharapova,
“Spectral and temporal properties of type-II parametric down-conversion: The impact
of losses during state generation,” Physical Review Research, vol. 7, no.
3, Art. no. 033122, 2025, doi: 10.1103/zp72-7qwl.'
mla: 'Kopylov, Denis A., et al. “Spectral and Temporal Properties of Type-II Parametric
down-Conversion: The Impact of Losses during State Generation.” Physical Review
Research, vol. 7, no. 3, 033122, American Physical Society (APS), 2025, doi:10.1103/zp72-7qwl.'
short: D.A. Kopylov, M. Stefszky, T. Meier, C. Silberhorn, P.R. Sharapova, Physical
Review Research 7 (2025).
date_created: 2025-12-05T09:33:36Z
date_updated: 2025-12-05T09:55:22Z
department:
- _id: '15'
- _id: '569'
- _id: '170'
- _id: '293'
- _id: '288'
- _id: '230'
- _id: '623'
- _id: '429'
- _id: '35'
doi: 10.1103/zp72-7qwl
intvolume: ' 7'
issue: '3'
language:
- iso: eng
project:
- _id: '266'
name: 'PhoQC: Photonisches Quantencomputing'
- _id: '53'
name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten
zu funktionellen Strukturen'
- _id: '56'
name: TRR 142 - Project Area C
- _id: '174'
name: 'TRR 142 ; TP: C10: Erzeugung und Charakterisierung von Quantenlicht in nichtlinearen
Systemen: Eine theoretische Analyse'
publication: Physical Review Research
publication_identifier:
issn:
- 2643-1564
publication_status: published
publisher: American Physical Society (APS)
status: public
title: 'Spectral and temporal properties of type-II parametric down-conversion: The
impact of losses during state generation'
type: journal_article
user_id: '16199'
volume: 7
year: '2025'
...
---
_id: '62913'
author:
- first_name: Anna
full_name: Hunstig, Anna
id: '73659'
last_name: Hunstig
- first_name: Sebastian
full_name: Peitz, Sebastian
id: '47427'
last_name: Peitz
orcid: 0000-0002-3389-793X
- first_name: Hendrik
full_name: Rose, Hendrik
id: '55958'
last_name: Rose
orcid: 0000-0002-3079-5428
- first_name: Torsten
full_name: Meier, Torsten
id: '344'
last_name: Meier
orcid: 0000-0001-8864-2072
citation:
ama: 'Hunstig A, Peitz S, Rose H, Meier T. Accelerating the analysis of optical
quantum systems using the Koopman operator. In: 2024 IEEE 63rd Conference on
Decision and Control (CDC). IEEE; 2025. doi:10.1109/cdc56724.2024.10886589'
apa: Hunstig, A., Peitz, S., Rose, H., & Meier, T. (2025). Accelerating the
analysis of optical quantum systems using the Koopman operator. 2024 IEEE 63rd
Conference on Decision and Control (CDC). https://doi.org/10.1109/cdc56724.2024.10886589
bibtex: '@inproceedings{Hunstig_Peitz_Rose_Meier_2025, title={Accelerating the analysis
of optical quantum systems using the Koopman operator}, DOI={10.1109/cdc56724.2024.10886589},
booktitle={2024 IEEE 63rd Conference on Decision and Control (CDC)}, publisher={IEEE},
author={Hunstig, Anna and Peitz, Sebastian and Rose, Hendrik and Meier, Torsten},
year={2025} }'
chicago: Hunstig, Anna, Sebastian Peitz, Hendrik Rose, and Torsten Meier. “Accelerating
the Analysis of Optical Quantum Systems Using the Koopman Operator.” In 2024
IEEE 63rd Conference on Decision and Control (CDC). IEEE, 2025. https://doi.org/10.1109/cdc56724.2024.10886589.
ieee: 'A. Hunstig, S. Peitz, H. Rose, and T. Meier, “Accelerating the analysis of
optical quantum systems using the Koopman operator,” 2025, doi: 10.1109/cdc56724.2024.10886589.'
mla: Hunstig, Anna, et al. “Accelerating the Analysis of Optical Quantum Systems
Using the Koopman Operator.” 2024 IEEE 63rd Conference on Decision and Control
(CDC), IEEE, 2025, doi:10.1109/cdc56724.2024.10886589.
short: 'A. Hunstig, S. Peitz, H. Rose, T. Meier, in: 2024 IEEE 63rd Conference on
Decision and Control (CDC), IEEE, 2025.'
date_created: 2025-12-05T09:37:58Z
date_updated: 2025-12-05T09:40:24Z
department:
- _id: '15'
- _id: '170'
- _id: '293'
- _id: '230'
- _id: '623'
- _id: '35'
doi: 10.1109/cdc56724.2024.10886589
language:
- iso: eng
project:
- _id: '266'
name: 'PhoQC: Photonisches Quantencomputing'
publication: 2024 IEEE 63rd Conference on Decision and Control (CDC)
publication_status: published
publisher: IEEE
status: public
title: Accelerating the analysis of optical quantum systems using the Koopman operator
type: conference
user_id: '16199'
year: '2025'
...
---
_id: '62980'
abstract:
- lang: eng
text: We introduce a new classification of multimode states with a fixed
number of photons. This classification is based on the factorizability of homogeneous
multivariate polynomials and is invariant under unitary transformations. The classes
physically correspond to field excitations in terms of single and multiple photons,
each of which is in an arbitrary irreducible superposition of quantized modes.
We further show how the transitions between classes are rendered possible by photon
addition, photon subtraction, and photon-projection nonlinearities. We explicitly
put forward a design for a multilayer interferometer in which the states for different
classes can be generated with state-of-the-art experimental techniques. Limitations
of the proposed designs are analyzed using the introduced classification, providing
a benchmark for the robustness of certain states and classes.
article_number: '033062'
author:
- first_name: Denis A.
full_name: Kopylov, Denis A.
last_name: Kopylov
- first_name: Christian
full_name: Offen, Christian
id: '85279'
last_name: Offen
orcid: 0000-0002-5940-8057
- first_name: Laura
full_name: Ares, Laura
last_name: Ares
- first_name: Boris Edgar
full_name: Wembe Moafo, Boris Edgar
id: '95394'
last_name: Wembe Moafo
- first_name: Sina
full_name: Ober-Blöbaum, Sina
id: '16494'
last_name: Ober-Blöbaum
- first_name: Torsten
full_name: Meier, Torsten
id: '344'
last_name: Meier
orcid: 0000-0001-8864-2072
- first_name: Polina R.
full_name: Sharapova, Polina R.
id: '60286'
last_name: Sharapova
- first_name: Jan
full_name: Sperling, Jan
id: '75127'
last_name: Sperling
orcid: 0000-0002-5844-3205
citation:
ama: Kopylov DA, Offen C, Ares L, et al. Multiphoton, multimode state classification
for nonlinear optical circuits. Physical Review Research. 2025;7(3). doi:10.1103/sv6z-v1gk
apa: Kopylov, D. A., Offen, C., Ares, L., Wembe Moafo, B. E., Ober-Blöbaum, S.,
Meier, T., Sharapova, P. R., & Sperling, J. (2025). Multiphoton, multimode
state classification for nonlinear optical circuits. Physical Review Research,
7(3), Article 033062. https://doi.org/10.1103/sv6z-v1gk
bibtex: '@article{Kopylov_Offen_Ares_Wembe Moafo_Ober-Blöbaum_Meier_Sharapova_Sperling_2025,
title={Multiphoton, multimode state classification for nonlinear optical circuits},
volume={7}, DOI={10.1103/sv6z-v1gk},
number={3033062}, journal={Physical Review Research}, publisher={American Physical
Society (APS)}, author={Kopylov, Denis A. and Offen, Christian and Ares, Laura
and Wembe Moafo, Boris Edgar and Ober-Blöbaum, Sina and Meier, Torsten and Sharapova,
Polina R. and Sperling, Jan}, year={2025} }'
chicago: Kopylov, Denis A., Christian Offen, Laura Ares, Boris Edgar Wembe Moafo,
Sina Ober-Blöbaum, Torsten Meier, Polina R. Sharapova, and Jan Sperling. “Multiphoton,
Multimode State Classification for Nonlinear Optical Circuits.” Physical Review
Research 7, no. 3 (2025). https://doi.org/10.1103/sv6z-v1gk.
ieee: 'D. A. Kopylov et al., “Multiphoton, multimode state classification
for nonlinear optical circuits,” Physical Review Research, vol. 7, no.
3, Art. no. 033062, 2025, doi: 10.1103/sv6z-v1gk.'
mla: Kopylov, Denis A., et al. “Multiphoton, Multimode State Classification for
Nonlinear Optical Circuits.” Physical Review Research, vol. 7, no. 3, 033062,
American Physical Society (APS), 2025, doi:10.1103/sv6z-v1gk.
short: D.A. Kopylov, C. Offen, L. Ares, B.E. Wembe Moafo, S. Ober-Blöbaum, T. Meier,
P.R. Sharapova, J. Sperling, Physical Review Research 7 (2025).
date_created: 2025-12-09T09:08:39Z
date_updated: 2025-12-09T09:10:01Z
department:
- _id: '15'
- _id: '569'
- _id: '170'
- _id: '293'
- _id: '706'
- _id: '636'
- _id: '35'
- _id: '230'
- _id: '429'
- _id: '623'
doi: 10.1103/sv6z-v1gk
intvolume: ' 7'
issue: '3'
language:
- iso: eng
project:
- _id: '53'
name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten
zu funktionellen Strukturen'
- _id: '56'
name: TRR 142 - Project Area C
- _id: '174'
name: 'TRR 142 ; TP: C10: Erzeugung und Charakterisierung von Quantenlicht in nichtlinearen
Systemen: Eine theoretische Analyse'
- _id: '266'
name: 'PhoQC: Photonisches Quantencomputing'
publication: Physical Review Research
publication_identifier:
issn:
- 2643-1564
publication_status: published
publisher: American Physical Society (APS)
status: public
title: Multiphoton, multimode state classification for nonlinear optical circuits
type: journal_article
user_id: '16199'
volume: 7
year: '2025'
...
---
_id: '62979'
abstract:
- lang: eng
text: We introduce a new classification of multimode states with a fixed number
of photons. This classification is based on the factorizability of homogeneous
multivariate polynomials and is invariant under unitary transformations. The classes
physically correspond to field excitations in terms of single and multiple photons,
each of which being in an arbitrary irreducible superposition of quantized modes.
We further show how the transitions between classes are rendered possible by photon
addition, photon subtraction, and photon-projection nonlinearities. We explicitly
put forward a design for a multilayer interferometer in which the states for different
classes can be generated with state-of-the-art experimental techniques. Limitations
of the proposed designs are analyzed using the introduced classification, providing
a benchmark for the robustness of certain states and classes.
author:
- first_name: Torsten
full_name: Meier, Torsten
id: '344'
last_name: Meier
orcid: 0000-0001-8864-2072
- first_name: Polina R.
full_name: Sharapova, Polina R.
id: '60286'
last_name: Sharapova
- first_name: Jan
full_name: Sperling, Jan
id: '75127'
last_name: Sperling
orcid: 0000-0002-5844-3205
- first_name: Sina
full_name: Ober-Blöbaum, Sina
id: '16494'
last_name: Ober-Blöbaum
- first_name: Boris Edgar
full_name: Wembe Moafo, Boris Edgar
id: '95394'
last_name: Wembe Moafo
- first_name: Christian
full_name: Offen, Christian
id: '85279'
last_name: Offen
orcid: 0000-0002-5940-8057
citation:
ama: Meier T, Sharapova PR, Sperling J, Ober-Blöbaum S, Wembe Moafo BE, Offen C.
Multiphoton, multimode state classification for nonlinear optical circuits. Published
online 2025.
apa: Meier, T., Sharapova, P. R., Sperling, J., Ober-Blöbaum, S., Wembe Moafo, B.
E., & Offen, C. (2025). Multiphoton, multimode state classification for
nonlinear optical circuits.
bibtex: '@article{Meier_Sharapova_Sperling_Ober-Blöbaum_Wembe Moafo_Offen_2025,
title={Multiphoton, multimode state classification for nonlinear optical circuits},
author={Meier, Torsten and Sharapova, Polina R. and Sperling, Jan and Ober-Blöbaum,
Sina and Wembe Moafo, Boris Edgar and Offen, Christian}, year={2025} }'
chicago: Meier, Torsten, Polina R. Sharapova, Jan Sperling, Sina Ober-Blöbaum, Boris
Edgar Wembe Moafo, and Christian Offen. “Multiphoton, Multimode State Classification
for Nonlinear Optical Circuits,” 2025.
ieee: T. Meier, P. R. Sharapova, J. Sperling, S. Ober-Blöbaum, B. E. Wembe Moafo,
and C. Offen, “Multiphoton, multimode state classification for nonlinear optical
circuits.” 2025.
mla: Meier, Torsten, et al. Multiphoton, Multimode State Classification for Nonlinear
Optical Circuits. 2025.
short: T. Meier, P.R. Sharapova, J. Sperling, S. Ober-Blöbaum, B.E. Wembe Moafo,
C. Offen, (2025).
date_created: 2025-12-09T08:59:27Z
date_updated: 2025-12-09T09:10:23Z
department:
- _id: '15'
- _id: '170'
- _id: '293'
- _id: '706'
- _id: '636'
- _id: '230'
- _id: '623'
- _id: '429'
- _id: '35'
language:
- iso: eng
project:
- _id: '53'
name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten
zu funktionellen Strukturen'
- _id: '56'
name: TRR 142 - Project Area C
- _id: '174'
name: 'TRR 142 ; TP: C10: Erzeugung und Charakterisierung von Quantenlicht in nichtlinearen
Systemen: Eine theoretische Analyse'
- _id: '266'
name: 'PhoQC: Photonisches Quantencomputing'
status: public
title: Multiphoton, multimode state classification for nonlinear optical circuits
type: preprint
user_id: '16199'
year: '2025'
...
---
_id: '63021'
abstract:
- lang: eng
text: Bell measurements, entailing the projection onto one of the Bell states,
play a key role in quantum information and communication, where the outcome of
a variety of protocols crucially depends on the success probability of such measurements.
Although in the case of qubit systems, Bell measurements can be implemented using
only linear optical components, the same result is no longer true for qudits,
where at least the use of ancillary photons is required. In order to circumvent
this limitation, one possibility is to introduce nonlinear effects. In this work,
we adopt the latter approach and propose a scalable Bell measurement scheme for
high-dimensional states, exploiting multiple squeezer devices applied to a linear
optical circuit for discriminating the different Bell states. Our approach does
not require ancillary photons, is not limited by the dimension of the quantum
states, and is experimentally scalable, thus paving the way toward the realization
of an effective high-dimensional Bell measurement.
article_number: '023038'
author:
- first_name: Luca
full_name: Bianchi, Luca
last_name: Bianchi
- first_name: Carlo
full_name: Marconi, Carlo
last_name: Marconi
- first_name: Jan
full_name: Sperling, Jan
id: '75127'
last_name: Sperling
orcid: 0000-0002-5844-3205
- first_name: Davide
full_name: Bacco, Davide
last_name: Bacco
citation:
ama: Bianchi L, Marconi C, Sperling J, Bacco D. Predetection squeezing as a resource
for high-dimensional Bell-state measurements. Physical Review Research.
2025;7(2). doi:10.1103/physrevresearch.7.023038
apa: Bianchi, L., Marconi, C., Sperling, J., & Bacco, D. (2025). Predetection
squeezing as a resource for high-dimensional Bell-state measurements. Physical
Review Research, 7(2), Article 023038. https://doi.org/10.1103/physrevresearch.7.023038
bibtex: '@article{Bianchi_Marconi_Sperling_Bacco_2025, title={Predetection squeezing
as a resource for high-dimensional Bell-state measurements}, volume={7}, DOI={10.1103/physrevresearch.7.023038},
number={2023038}, journal={Physical Review Research}, publisher={American Physical
Society (APS)}, author={Bianchi, Luca and Marconi, Carlo and Sperling, Jan and
Bacco, Davide}, year={2025} }'
chicago: Bianchi, Luca, Carlo Marconi, Jan Sperling, and Davide Bacco. “Predetection
Squeezing as a Resource for High-Dimensional Bell-State Measurements.” Physical
Review Research 7, no. 2 (2025). https://doi.org/10.1103/physrevresearch.7.023038.
ieee: 'L. Bianchi, C. Marconi, J. Sperling, and D. Bacco, “Predetection squeezing
as a resource for high-dimensional Bell-state measurements,” Physical Review
Research, vol. 7, no. 2, Art. no. 023038, 2025, doi: 10.1103/physrevresearch.7.023038.'
mla: Bianchi, Luca, et al. “Predetection Squeezing as a Resource for High-Dimensional
Bell-State Measurements.” Physical Review Research, vol. 7, no. 2, 023038,
American Physical Society (APS), 2025, doi:10.1103/physrevresearch.7.023038.
short: L. Bianchi, C. Marconi, J. Sperling, D. Bacco, Physical Review Research 7
(2025).
date_created: 2025-12-10T13:34:53Z
date_updated: 2025-12-10T13:36:11Z
department:
- _id: '623'
- _id: '15'
- _id: '170'
- _id: '706'
- _id: '429'
doi: 10.1103/physrevresearch.7.023038
intvolume: ' 7'
issue: '2'
language:
- iso: eng
publication: Physical Review Research
publication_identifier:
issn:
- 2643-1564
publication_status: published
publisher: American Physical Society (APS)
status: public
title: Predetection squeezing as a resource for high-dimensional Bell-state measurements
type: journal_article
user_id: '75127'
volume: 7
year: '2025'
...
---
_id: '62859'
abstract:
- lang: eng
text: Frequency-filtered photon correlations have been proven to be extremely
useful in grasping how the detection process alters photon statistics. Harnessing
the spectral correlations also permits refinement of the emission and unraveling
of previously hidden strong correlations in a plethora of quantum-optical systems
under continuous-wave excitation. In this work, we investigate such correlations
for time-dependent excitation and develop a methodology to compute efficiently
time-integrated correlations, which are at the heart of the photon-counting theory,
and subsequently apply it to analyze the photon emission of pulsed systems. By
combining this formalism with the —which facilitates frequency-resolved correlations—we
demonstrate how spectral filtering enhances single-photon purity and suppresses
multiphoton noise in time-bin-encoded quantum states. Specifically, filtering
the central spectral peak of a dynamically driven two-level system boosts temporal
coherence and improves the fidelity of time-bin entanglement preparation, even
under conditions favoring multiphoton emission. These results establish spectral
filtering as a critical tool for tailoring photon statistics in pulsed quantum
light sources.
article_number: '033296'
author:
- first_name: Santiago
full_name: Bermúdez-Feijóo, Santiago
last_name: Bermúdez-Feijóo
- first_name: Eduardo
full_name: Zubizarreta Casalengua, Eduardo
last_name: Zubizarreta Casalengua
- first_name: Kai
full_name: Müller, Kai
last_name: Müller
- first_name: Klaus
full_name: Jöns, Klaus
id: '85353'
last_name: Jöns
citation:
ama: Bermúdez-Feijóo S, Zubizarreta Casalengua E, Müller K, Jöns K. Spectral correlations
of dynamical resonance fluorescence. Physical Review Research. 2025;7(3).
doi:10.1103/jmy9-bd3l
apa: Bermúdez-Feijóo, S., Zubizarreta Casalengua, E., Müller, K., & Jöns, K.
(2025). Spectral correlations of dynamical resonance fluorescence. Physical
Review Research, 7(3), Article 033296. https://doi.org/10.1103/jmy9-bd3l
bibtex: '@article{Bermúdez-Feijóo_Zubizarreta Casalengua_Müller_Jöns_2025, title={Spectral
correlations of dynamical resonance fluorescence}, volume={7}, DOI={10.1103/jmy9-bd3l},
number={3033296}, journal={Physical Review Research}, publisher={American Physical
Society (APS)}, author={Bermúdez-Feijóo, Santiago and Zubizarreta Casalengua,
Eduardo and Müller, Kai and Jöns, Klaus}, year={2025} }'
chicago: Bermúdez-Feijóo, Santiago, Eduardo Zubizarreta Casalengua, Kai Müller,
and Klaus Jöns. “Spectral Correlations of Dynamical Resonance Fluorescence.” Physical
Review Research 7, no. 3 (2025). https://doi.org/10.1103/jmy9-bd3l.
ieee: 'S. Bermúdez-Feijóo, E. Zubizarreta Casalengua, K. Müller, and K. Jöns, “Spectral
correlations of dynamical resonance fluorescence,” Physical Review Research,
vol. 7, no. 3, Art. no. 033296, 2025, doi: 10.1103/jmy9-bd3l.'
mla: Bermúdez-Feijóo, Santiago, et al. “Spectral Correlations of Dynamical Resonance
Fluorescence.” Physical Review Research, vol. 7, no. 3, 033296, American
Physical Society (APS), 2025, doi:10.1103/jmy9-bd3l.
short: S. Bermúdez-Feijóo, E. Zubizarreta Casalengua, K. Müller, K. Jöns, Physical
Review Research 7 (2025).
date_created: 2025-12-04T12:19:04Z
date_updated: 2025-12-11T12:52:24Z
department:
- _id: '623'
- _id: '15'
- _id: '429'
- _id: '642'
doi: 10.1103/jmy9-bd3l
intvolume: ' 7'
issue: '3'
language:
- iso: eng
publication: Physical Review Research
publication_identifier:
issn:
- 2643-1564
publication_status: published
publisher: American Physical Society (APS)
status: public
title: Spectral correlations of dynamical resonance fluorescence
type: journal_article
user_id: '48188'
volume: 7
year: '2025'
...