@article{59273,
  abstract     = {{Ferroelectric domain walls (DWs) are promising structures for assembling future nano-electronic circuit elements on a larger scale since reporting domain wall currents of up to 1 mA per single DW. One key requirement hereto is their reproducible manufacturing by gaining preparative control over domain size and domain wall conductivity (DWC). To date, most works on DWC have focused on exploring the fundamental electrical properties of individual DWs within single-shot experiments, with an emphasis on quantifying the origins of DWC. Very few reports exist when it comes to comparing the DWC properties between two separate DWs, and literally nothing exists where issues of reproducibility in DWC devices have been addressed. To fill this gap while facing the challenge of finding guidelines for achieving predictable DWC performance, we report on a procedure that allows us to reproducibly prepare single hexagonal domains of a predefined diameter into uniaxial ferroelectric lithium niobate single crystals of 200 and 300 μm thickness, respectively. We show that the domain diameter can be controlled with an uncertainty of a few percent. As-grown DWs are then subjected to a standard procedure of current-limited high-voltage DWC enhancement, and they repetitively reach a DWC increase of six orders of magnitude. While all resulting DWs show significantly enhanced DWC values, their individual current–voltage (I–V) characteristics exhibit different shapes, which can be explained by variations in their 3D real structure reflecting local heterogeneities by defects, DW pinning, and surface-near DW inclination.}},
  author       = {{Ratzenberger, Julius and Kiseleva, Iuliia and Koppitz, Boris and Beyreuther, Elke and Zahn, Manuel and Gössel, Joshua and Hegarty, Peter A. and Amber, Zeeshan H. and Rüsing, Michael and Eng, Lukas M.}},
  issn         = {{0021-8979}},
  journal      = {{Journal of Applied Physics}},
  number       = {{10}},
  pages        = {{104302}},
  publisher    = {{AIP Publishing}},
  title        = {{{Toward the reproducible fabrication of conductive ferroelectric domain walls into lithium niobate bulk single crystals}}},
  doi          = {{10.1063/5.0219300}},
  volume       = {{136}},
  year         = {{2024}},
}

@article{59274,
  abstract     = {{Recently, ion exchange (IE) has been used to periodically modify the coercive field (Ec) of the crystal prior to periodic poling, to fabricate fine-pitch domain structures in Rb-doped KTiOPO4 (RKTP). Here, we use micro-Raman spectroscopy to understand the impact of IE on the vibrational modes related to the Rb/K lattice sites, TiO octahedra, and PO4 tetrahedra, which all form the basis of the RKTP crystal structure. We analyze the Raman spectra of three different RKTP samples: (1) a RKTP sample that shows a poled domain grating only, (2) a RKTP sample that has an Ec grating only, and (3) a RKTP sample that has both an Ec and a domain grating of the nominally same spacing. This allows us to determine the impact of IE on the vibrational modes of RKTP. We characterize the changes in the lower Raman peaks related to the alkali-metal ions, as well as observe lattice modifications induced by the incorporation of Rb+ that extend further into the crystal bulk than the expected IE depth. Moreover, the influence of IE on the domain walls is also manifested in their Raman peak shift. We discuss our results in terms of the deformation of the PO4and TiO groups. Our results highlight the intricate impact of IE on the crystal structure and how it facilitates periodic poling, paving the way for further development of the Ec-engineering technique.}},
  author       = {{Lee, Cherrie S. J. and Canalias, Carlota and Buschbeck, Robin and Koppitz, Boris and Hempel, Franz and Amber, Zeeshan and Eng, Lukas M. and Rüsing, Michael}},
  issn         = {{2469-9950}},
  journal      = {{Physical Review B}},
  number       = {{21}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Impact of ion exchange on vibrational modes in Rb-doped KTiOPO4: A Raman spectroscopy study on the interplay between ion exchange and polarization switching}}},
  doi          = {{10.1103/physrevb.110.214115}},
  volume       = {{110}},
  year         = {{2024}},
}

@article{59275,
  abstract     = {{Studying and understanding many‐body interactions, particularly electron‐boson interactions, is essential for a deeper elucidation of fundamental physical phenomena and the development of novel material functionalities. Here, this aspect is explored in the weak itinerant ferromagnet LaCo2P2 by means of momentum‐resolved photoelectron spectroscopy (ARPES) and first‐principles calculations. The detailed ARPES patterns enable to unveil bulk and surface bands, spin splittings due to Rashba and exchange interactions, as well as the evolution of bands with temperature, which altogether creates a solid foundation for theoretical studies. The latter has allowed to establish the impact of electron‐boson interactions on the electronic structure, that are reflected in its strong renormalization driven by electron‐magnon interaction and the emergence of distinctive kinks of surface and bulk electron bands due to significant electron‐phonon coupling. Our results highlight the distinct impact of electron‐boson interactions on the electronic structure, particularly on the itinerant d states. Similar electronic states are observed in the isostructural iron pnictides, where electron‐boson interactions play a crucial role in the emergence of superconductivity. It is believed that further studies of material systems involving both magnetically active d‐ and f‐sublattices will reveal more advanced phenomena in the bulk and at distinct surfaces, driven by a combination of factors including Rashba and Kondo effects, exchange magnetism, and electron‐boson interactions.}},
  author       = {{Usachov, D. Yu. and Ali, K. and Poelchen, G. and Mende, M. and Schulz, S. and Peters, M. and Bokai, K. and Sklyadneva, I. Yu. and Stolyarov, V. and Chulkov, E. V. and Kliemt, K. and Paischer, S. and Buczek, P. A. and Heid, R. and Hempel, F. and Rüsing, Michael and Ernst, A. and Krellner, C. and Eremeev, S. V. and Vyalikh, D. V.}},
  issn         = {{2751-1200}},
  journal      = {{Advanced Physics Research}},
  publisher    = {{Wiley}},
  title        = {{{Unveiling Electron‐Phonon and Electron‐Magnon Interactions in the Weak Itinerant Ferromagnet LaCo2P2}}},
  doi          = {{10.1002/apxr.202400137}},
  year         = {{2024}},
}

@article{54966,
  abstract     = {{Piezoresponse force microscopy (PFM) is one of the most widespread methods for investigating and visualizing ferroelectric domain structures down to the nanometer length scale. PFM makes use of the direct coupling of the piezoelectric response to the crystal lattice, and hence, it is most often applied to spatially map the three-dimensional (3D) near-surface domain distribution of any polar or ferroic sample. Nonetheless, since most samples investigated by PFM are at least semiconducting or fully insulating, the electric ac field emerging from the conductive scanning force microscopy (SFM) tip penetrates the sample and, hence, may also couple to polar features that are deeply buried into the bulk of the sample under investigation. Thus, in the work presented here, we experimentally and theoretically explore the contrast and depth resolution capabilities of PFM, by analyzing the dependence of several key parameters. These key parameters include the depth of the buried feature, i.e., here a domain wall (DW), as well as PFM-relevant technical parameters such as the tip radius, the PFM drive voltage and frequency, and the signal-to-noise ratio. The theoretical predictions are experimentally verified using x-cut periodically poled lithium niobate single crystals that are specially prepared into wedge-shaped samples, in order to allow the buried feature, here the DW, to be “positioned” at any depth into the bulk. This inspection essentially contributes to the fundamental understanding in PFM contrast analysis and to the reconstruction of 3D domain structures down to a 1 μm-penetration depth into the sample.}},
  author       = {{Roeper, Matthias and Seddon, Samuel D. and Amber, Zeeshan H. and Rüsing, Michael and Eng, Lukas M.}},
  issn         = {{0021-8979}},
  journal      = {{Journal of Applied Physics}},
  keywords     = {{Ferroelectrics, lithium niobate, piezoresponse force microscopy}},
  number       = {{22}},
  publisher    = {{AIP Publishing}},
  title        = {{{Depth resolution in piezoresponse force microscopy}}},
  doi          = {{10.1063/5.0206784}},
  volume       = {{135}},
  year         = {{2024}},
}

@misc{59259,
  author       = {{Schwabe, Tobias and Rüsing, Michael and Staal, Niels and Schwengelbeck, Max and Bollmers, Laura and Padberg, Laura and Eigner, Christof and Silberhorn, Christine and Scheytt, J. Christoph}},
  publisher    = {{Zenodo}},
  title        = {{{Quantum photonic systems in CMOS compatible silicon nitride technology }}},
  doi          = {{10.5281/zenodo.15124929}},
  year         = {{2024}},
}

@article{47997,
  abstract     = {{The crystal family of potassium titanyl phosphate (KTiOPO4) is a promising material group for applications in quantum and nonlinear optics. The fabrication of low-loss optical waveguides, as well as high-grade periodically poled ferroelectric domain structures, requires a profound understanding of the material properties and crystal structure. In this regard, Raman spectroscopy offers the possibility to study and visualize domain structures, strain, defects, and the local stoichiometry, which are all factors impacting device performance. However, the accurate interpretation of Raman spectra and their changes with respect to extrinsic and intrinsic defects requires a thorough assignment of the Raman modes to their respective crystal features, which to date is only partly conducted based on phenomenological modelling. To address this issue, we calculated the phonon spectra of potassium titanyl phosphate and the related compounds rubidium titanyl phosphate (RbTiOPO4) and potassium titanyl arsenate (KTiOAsO4) based on density functional theory and compared them with experimental data. Overall, this allows us to assign various spectral features to eigenmodes of lattice substructures with improved detail compared to previous assignments. Nevertheless, the analysis also shows that not all features of the spectra can unambigiously be explained yet. A possible explanation might be that defects or long range fields not included in the modeling play a crucial rule for the resulting Raman spectrum. In conclusion, this work provides an improved foundation into the vibrational properties in the KTiOPO4 material family.}},
  author       = {{Neufeld, Sergej and Gerstmann, Uwe and Padberg, Laura and Eigner, Christof and Berth, Gerhard and Silberhorn, Christine and Eng, Lukas M. and Schmidt, Wolf Gero and Rüsing, Michael}},
  issn         = {{2073-4352}},
  journal      = {{Crystals}},
  keywords     = {{Inorganic Chemistry, Condensed Matter Physics, General Materials Science, General Chemical Engineering}},
  number       = {{10}},
  publisher    = {{MDPI AG}},
  title        = {{{Vibrational Properties of the Potassium Titanyl Phosphate Crystal Family}}},
  doi          = {{10.3390/cryst13101423}},
  volume       = {{13}},
  year         = {{2023}},
}

@article{48349,
  abstract     = {{<jats:p>We report a titanium indiffused waveguide resonator featuring an integrated electro-optic modulator for cavity length stabilisation that produces close to 5 dB of squeezed light at 1550 nm (2.4 dB directly measured). The resonator is locked on resonance for tens of minutes with 70 mW of SH light incident on the cavity, demonstrating that photorefraction can be mitigated. Squeezed light production concurrent with cavity length stabilisation utilising the integrated EOM is demonstrated. The device demonstrates the suitability of this platform for squeezed light generation in network applications, where stabilisation to the reference field is typically necessary.</jats:p>}},
  author       = {{Stefszky, M. and vom Bruch, F. and Santandrea, M. and Ricken, R. and Quiring, V. and Eigner, C. and Herrmann, H and Silberhorn, C}},
  issn         = {{1094-4087}},
  journal      = {{Optics Express}},
  keywords     = {{Atomic and Molecular Physics, and Optics}},
  number       = {{21}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Lithium niobate waveguide squeezer with integrated cavity length stabilisation for network applications}}},
  doi          = {{10.1364/oe.498423}},
  volume       = {{31}},
  year         = {{2023}},
}

@article{48399,
  abstract     = {{<jats:p>Quantum photonic processing via electro-optic components typically requires electronic links across different operation environments, especially when interfacing cryogenic components such as superconducting single photon detectors with room-temperature control and readout electronics. However, readout and driving electronics can introduce detrimental parasitic effects. Here we show an all-optical control and readout of a superconducting nanowire single photon detector (SNSPD), completely electrically decoupled from room temperature electronics. We provide the operation power for the superconducting detector via a cryogenic photodiode, and readout single photon detection signals via a cryogenic electro-optic modulator in the same cryostat. This method opens the possibility for control and readout of superconducting circuits, and feedforward for photonic quantum computing.</jats:p>}},
  author       = {{Thiele, Frederik and Hummel, Thomas and McCaughan, Adam N. and Brockmeier, Julian and Protte, Maximilian and Quiring, Victor and Lengeling, Sebastian and Eigner, Christof and Silberhorn, Christine and Bartley, Tim}},
  issn         = {{1094-4087}},
  journal      = {{Optics Express}},
  keywords     = {{Atomic and Molecular Physics, and Optics}},
  number       = {{20}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{All optical operation of a superconducting photonic interface}}},
  doi          = {{10.1364/oe.492035}},
  volume       = {{31}},
  year         = {{2023}},
}

@article{54852,
  abstract     = {{<jats:p>The crystal family of potassium titanyl phosphate (KTiOPO4) is a promising material group for applications in quantum and nonlinear optics. The fabrication of low-loss optical waveguides, as well as high-grade periodically poled ferroelectric domain structures, requires a profound understanding of the material properties and crystal structure. In this regard, Raman spectroscopy offers the possibility to study and visualize domain structures, strain, defects, and the local stoichiometry, which are all factors impacting device performance. However, the accurate interpretation of Raman spectra and their changes with respect to extrinsic and intrinsic defects requires a thorough assignment of the Raman modes to their respective crystal features, which to date is only partly conducted based on phenomenological modelling. To address this issue, we calculated the phonon spectra of potassium titanyl phosphate and the related compounds rubidium titanyl phosphate (RbTiOPO4) and potassium titanyl arsenate (KTiOAsO4) based on density functional theory and compared them with experimental data. Overall, this allows us to assign various spectral features to eigenmodes of lattice substructures with improved detail compared to previous assignments. Nevertheless, the analysis also shows that not all features of the spectra can unambigiously be explained yet. A possible explanation might be that defects or long range fields not included in the modeling play a crucial rule for the resulting Raman spectrum. In conclusion, this work provides an improved foundation into the vibrational properties in the KTiOPO4 material family.</jats:p>}},
  author       = {{Neufeld, Sergej and Gerstmann, Uwe and Padberg, Laura and Eigner, Christof and Berth, Gerhard and Silberhorn, Christine and Eng, Lukas M. and Schmidt, Wolf Gero and Rüsing, Michael}},
  issn         = {{2073-4352}},
  journal      = {{Crystals}},
  number       = {{10}},
  publisher    = {{MDPI AG}},
  title        = {{{Vibrational Properties of the Potassium Titanyl Phosphate Crystal Family}}},
  doi          = {{10.3390/cryst13101423}},
  volume       = {{13}},
  year         = {{2023}},
}

@article{42158,
  author       = {{Lüders, Carolin and Gil-Lopez, Jano and Allgaier, Markus and Brecht, Benjamin and Aßmann, Marc and Silberhorn, Christine and Bayer, Manfred}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  keywords     = {{General Physics and Astronomy}},
  number       = {{1}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Tailored Frequency Conversion Makes Infrared Light Visible for Streak Cameras}}},
  doi          = {{10.1103/physrevapplied.19.014072}},
  volume       = {{19}},
  year         = {{2023}},
}

@article{45485,
  author       = {{Kruse, Stephan and Serino, Laura and Folge, Patrick Fabian and Echeverria Oviedo, Dana and Bhattacharjee, Abhinandan and Stefszky, Michael and Scheytt, J. Christoph and Brecht, Benjamin and Silberhorn, Christine}},
  issn         = {{1041-1135}},
  journal      = {{IEEE Photonics Technology Letters}},
  keywords     = {{Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials}},
  number       = {{14}},
  pages        = {{769--772}},
  publisher    = {{Institute of Electrical and Electronics Engineers (IEEE)}},
  title        = {{{A Pulsed Lidar System With Ultimate Quantum Range Accuracy}}},
  doi          = {{10.1109/lpt.2023.3277515}},
  volume       = {{35}},
  year         = {{2023}},
}

@article{45850,
  abstract     = {{Interference between single photons is key for many quantum optics experiments and applications in quantum technologies, such as quantum communication or computation. It is advantageous to operate the systems at telecommunication wavelengths and to integrate the setups for these applications in order to improve stability, compactness and scalability. A new promising material platform for integrated quantum optics is lithium niobate on insulator (LNOI). Here, we realise Hong-Ou-Mandel (HOM) interference between telecom photons from an engineered parametric down-conversion source in an LNOI directional coupler. The coupler has been designed and fabricated in house and provides close to perfect balanced beam splitting. We obtain a raw HOM visibility of (93.5 ± 0.7) %, limited mainly by the source performance and in good agreement with off-chip measurements. This lays the foundation for more sophisticated quantum experiments in LNOI.}},
  author       = {{Babel, Silia and Bollmers, Laura and Massaro, Marcello and Luo, Kai Hong and Stefszky, Michael and Pegoraro, Federico and Held, Philip and Herrmann, Harald and Eigner, Christof and Brecht, Benjamin and Padberg, Laura and Silberhorn, Christine}},
  issn         = {{1094-4087}},
  journal      = {{Optics Express}},
  keywords     = {{Atomic and Molecular Physics, and Optics}},
  number       = {{14}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Demonstration of Hong-Ou-Mandel interference in an LNOI directional coupler}}},
  doi          = {{10.1364/oe.484126}},
  volume       = {{31}},
  year         = {{2023}},
}

@article{46138,
  abstract     = {{<jats:p>This work reports a fully guided setup for single-mode squeezing on integrated titanium-indiffused periodically poled nonlinear resonators. A continuous-wave laser beam is delivered and the squeezed field is collected by single-mode fibers; up to −3.17(9) dB of useful squeezing is available in fibers. To showcase the usefulness of such a fiber-coupled device, we applied the generated squeezed light in a fiber-based phase sensing experiment, showing a quantum enhancement in the signal-to-noise ratio of 0.35 dB. Moreover, our investigation of the effect of photorefraction on the cavity resonance condition suggests that it causes system instabilities at high powers.</jats:p>}},
  author       = {{Domeneguetti, Renato and Stefszky, Michael and Herrmann, Harald and Silberhorn, Christine and Andersen, Ulrik L. and Neergaard-Nielsen, Jonas S. and Gehring, Tobias}},
  issn         = {{0146-9592}},
  journal      = {{Optics Letters}},
  keywords     = {{Atomic and Molecular Physics, and Optics}},
  number       = {{11}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Fully guided and phase locked Ti:PPLN waveguide squeezing for applications in quantum sensing}}},
  doi          = {{10.1364/ol.486654}},
  volume       = {{48}},
  year         = {{2023}},
}

@article{46644,
  abstract     = {{A reliable, but cost-effective generation of single-photon states is key for practical quantum communication systems. For real-world deployment, waveguide sources offer optimum compatibility with fiber networks and can be embedded in hybrid integrated modules. Here, we present what we believe to be the first chip-size fully integrated fiber-coupled heralded single photon source (HSPS) module based on a hybrid integration of a nonlinear lithium niobate waveguide into a polymer board. Photon pairs at 810 nm (signal) and 1550 nm (idler) are generated via parametric down-conversion pumped at 532 nm in the LiNbO3 waveguide. The pairs are split in the polymer board and routed to separate output ports. The module has a size of (2 × 1) cm^2 and is fully fiber-coupled with one pump input fiber and two output fibers. We measure a heralded second-order correlation function of g_h(2)=0.05 with a heralding efficiency of η_h=3.5% at low pump powers}},
  author       = {{Kießler, Christian and Conradi, Hauke and Kleinert, Moritz and Quiring, Viktor and Herrmann, Harald and Silberhorn, Christine}},
  issn         = {{1094-4087}},
  journal      = {{Optics Express}},
  keywords     = {{Atomic and Molecular Physics, and Optics}},
  number       = {{14}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Fiber-coupled plug-and-play heralded single photon source based on Ti:LiNbO3 and polymer technology}}},
  doi          = {{10.1364/oe.487581}},
  volume       = {{31}},
  year         = {{2023}},
}

@inproceedings{43051,
  abstract     = {{We demonstrate the numerical and experimental realization of optimized optical traveling-wave antennas made of low-loss dielectric materials. These antennas exhibit highly directive radiation patterns and our studies reveal that this nature comes from two dominant guided TE modes excited in the waveguide-like director of the antenna, in addition to the leaky modes. The optimized antennas possess a broadband nature and have a nearunity radiation efficiency at an operational wavelength of 780 nm. Compared to the previously studied plasmonic antennas for photon emission, our all-dielectric approach demonstrates a new class of highly directional, low-loss, and broadband optical antennas.}},
  author       = {{Farheen, Henna and Yan, Lok-Yee and Leuteritz, Till and Qiao, Siqi and Spreyer, Florian and Schlickriede, Christian and Quiring, Viktor and Eigner, Christof and Silberhorn, Christine and Zentgraf, Thomas and Linden, Stefan and Myroshnychenko, Viktor and Förstner, Jens}},
  booktitle    = {{Integrated Optics: Devices, Materials, and Technologies XXVII}},
  editor       = {{García-Blanco, Sonia M. and Cheben, Pavel}},
  keywords     = {{tet_topic_opticalantenna}},
  pages        = {{124241E}},
  publisher    = {{SPIE}},
  title        = {{{Tailoring the directive nature of optical waveguide antennas}}},
  doi          = {{10.1117/12.2658921}},
  year         = {{2023}},
}

@inproceedings{61362,
  abstract     = {{<jats:p>We study the interaction of gray tracking and DC ionic conductivity in Potassium Titanyl Phosphate (KTiOPO<jats:sub>4</jats:sub>, KTP) and present a novel way to reduce conductivity via a potassium nitrate treatment improving the device quality.</jats:p>}},
  author       = {{Eigner, Christof and Padberg, Laura and Quiring, Viktor and Bocchini, Adriana and Santandrea, Matteo and Gerstmann, Uwe and Schmidt, Wolf Gero and Silberhorn, Christine}},
  booktitle    = {{CLEO 2023}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Potassium Titanyl Phosphate Material Engineering Boosting Integrated Optical Source Performance}}},
  doi          = {{10.1364/cleo_at.2023.jw2a.57}},
  year         = {{2023}},
}

@article{38541,
  author       = {{Barkhofen, Sonja and Brecht, Benjamin and Silberhorn, Christine}},
  journal      = {{Physik in unserer Zeit}},
  number       = {{1}},
  pages        = {{10--11}},
  publisher    = {{Wiley}},
  title        = {{{Verschränkung wie am Fließband}}},
  doi          = {{https://doi.org/10.1002/piuz.202370107}},
  volume       = {{54}},
  year         = {{2023}},
}

@inproceedings{45578,
  abstract     = {{A frequency-flexible Nyquist pulse synthesizer is presented with optical pulse bandwidths up to fopt=100 GHz and repetition rates equal to fopt/9, fabricated in an electronic-photonic co-integrated platform utilizing linear on-chip drivers.}},
  author       = {{Kress, Christian and Schwabe, Tobias and Silberhorn, Christine and Scheytt, J. Christoph}},
  booktitle    = {{ Conference on Lasers and Electro-Optics (CLEO) 2023}},
  location     = {{San Jose, CA, USA}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Generation of 100 GHz Periodic Nyquist Pulses using Cascaded Mach-Zehnder Modulators in a Silicon Electronic-Photonic Platform}}},
  doi          = {{https://doi.org/10.1364/CLEO_SI.2023.SF1P.6}},
  year         = {{2023}},
}

@article{44081,
  author       = {{Serino, Laura and Gil López, Jano and Stefszky, Michael and Ricken, Raimund and Eigner, Christof and Brecht, Benjamin and Silberhorn, Christine}},
  issn         = {{2691-3399}},
  journal      = {{PRX Quantum}},
  keywords     = {{General Physics and Astronomy, Mathematical Physics, Applied Mathematics, Electronic, Optical and Magnetic Materials, Electrical and Electronic Engineering, General Computer Science}},
  number       = {{2}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Realization of a Multi-Output Quantum Pulse Gate for Decoding High-Dimensional Temporal Modes of Single-Photon States}}},
  doi          = {{10.1103/prxquantum.4.020306}},
  volume       = {{4}},
  year         = {{2023}},
}

@article{42648,
  abstract     = {{In real photonic quantum systems losses are an unavoidable factor limiting the scalability to many modes and particles, restraining their application in fields as quantum information and communication. For this reason, a considerable amount of engineering effort has been taken in order to improve the quality of particle sources and system components. At the same time, data analysis and collection methods based on post-selection have been used to mitigate the effect of particle losses. This has allowed for investigating experimentally multi-particle evolutions where the observer lacks knowledge about the system's intermediate propagation states. Nonetheless, the fundamental question how losses affect the behaviour of the surviving subset of a multi-particle system has not been investigated so far. For this reason, here we study the impact of particle losses in a quantum walk of two photons reconstructing the output probability distributions for one photon conditioned on the loss of the other in a known mode and temporal step of our evolution network. We present the underlying theoretical scheme that we have devised in order to model controlled particle losses, we describe an experimental platform capable of implementing our theory in a time multiplexing encoding. In the end we show how localized particle losses change the output distributions without altering their asymptotic spreading properties. Finally we devise a quantum civilization problem, a two walker generalisation of single particle recurrence processes.}},
  author       = {{Pegoraro, Federico and Held, Philip and Barkhofen, Sonja and Brecht, Benjamin and Silberhorn, Christine}},
  issn         = {{0031-8949}},
  journal      = {{Physica Scripta}},
  number       = {{3}},
  publisher    = {{IOP Publishing}},
  title        = {{{Dynamic conditioning of two particle discrete-time quantum walks}}},
  doi          = {{10.1088/1402-4896/acbcaa}},
  volume       = {{98}},
  year         = {{2023}},
}