@article{65094,
  abstract     = {{<jats:p>
                    The development of practical sensors for optical coherence tomography (OCT) with undetected photons requires miniaturization via integration. To be practical, these sensors must exhibit a large spectral bandwidth and a high brightness, which are linked to a high axial resolution and a sufficient signal-to-noise ratio, respectively. Here, we combine these requirements in a scheme for OCT measurements with undetected photons based on nonlinear
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                          <a:mi mathvariant="normal">O</a:mi>
                        </a:mrow>
                        <a:mn>3</a:mn>
                      </a:msub>
                    </a:math>
                    waveguides. We investigate the performance benchmarks of the commonly used SU(1,1) scheme in comparison to an induced-coherence scheme and find that the latter is actually better suited when implementing measurements with undetected photons in integrated systems. In both schemes, we perform pump-gain optimization and OCT measurements with undetected photons with an axial resolution as low as
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                      <d:mn>28</d:mn>
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                      <d:mtext fontfamily="times">μ</d:mtext>
                      <d:mrow>
                        <d:mi mathvariant="normal">m</d:mi>
                      </d:mrow>
                    </d:math>
                    .
                  </jats:p>}},
  author       = {{Roeder, Franz and Pollmann, René and Quiring, Viktor and Eigner, Christof and Brecht, Benjamin and Silberhorn, Christine}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  number       = {{3}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Toward integrated sensors for optimized optical coherence tomography with undetected photons}}},
  doi          = {{10.1103/cwsx-42c4}},
  volume       = {{25}},
  year         = {{2026}},
}

@article{65575,
  abstract     = {{<jats:p>For the ever-growing field of quantum information processing, large-scale, efficient multiport interferometers serving as photonic processors are required. In this context, the suitability of quantum walks as the interferometric base for universal computation has been theoretically proven. In this work, we bridge the gap between theoretical proposals and state-of-the-art experimental capabilities by providing the recipe for the implementation of a universal photonic processor in discrete-time quantum walks. Specifically, we present the protocol for translating arbitrary linear transformations into the coin and step operator of a quantum walk and map these to the experimental parameters of the established time-multiplexed platform [A. Schreiber , Phys. Rev. Lett. , 050502 (2010)]. We show that our interface is highly scalable and resource efficient due to the hybrid encoding consisting of multiple degrees of freedom. Finally, we prove that our system is highly resilient against experimental imperfections and show that it compares favorably against existing architectures.</jats:p>}},
  author       = {{Lammers, Jonas and Ares, Laura and Pegoraro, Federico and Held, Philip and Brecht, Benjamin and Sperling, Jan and Silberhorn, Christine}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  number       = {{5}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Resource-efficient universal photonic processors based on time-multiplexed hybrid architectures}}},
  doi          = {{10.1103/x99y-2sms}},
  volume       = {{25}},
  year         = {{2026}},
}

@article{61249,
  author       = {{Ai, Qiang and Wingenbach, Jan and Yang, Xinmiao and Wei, Jing and Hatzopoulos, Zaharias and Savvidis, Pavlos G. and Schumacher, Stefan and Ma, Xuekai and Gao, Tingge}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  number       = {{2}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Optically and remotely controlling localization of exciton-polariton condensates in a potential lattice}}},
  doi          = {{10.1103/physrevapplied.23.024029}},
  volume       = {{23}},
  year         = {{2025}},
}

@article{58933,
  author       = {{Ai, Qiang and Wingenbach, Jan and Yang, Xinmiao and Wei, Jing and Hatzopoulos, Zaharias and Savvidis, Pavlos G. and Schumacher, Stefan and Ma, Xuekai and Gao, Tingge}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  number       = {{2}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Optically and remotely controlling localization of exciton-polariton condensates in a potential lattice}}},
  doi          = {{10.1103/physrevapplied.23.024029}},
  volume       = {{23}},
  year         = {{2025}},
}

@article{51156,
  abstract     = {{Ferroelectric domain wall (DW) conductivity (DWC) can be attributed to two separate mechanisms: (a) the injection/ejection of charge carriers across the Schottky barrier formed at the (metal-)electrode-DW junction and (b) the transport of those charge carriers along the DW. Current-voltage (I-U) characteristics, recorded at variable temperatures from LiNbO3 (LNO) DWs, are clearly able to differentiate between these two contributions. Practically, they allow us to directly quantify the physical parameters relevant to the two mechanisms (a) and (b) mentioned above. These are, for example, the resistance of the DW, the saturation current, the ideality factor, and the Schottky barrier height of the electrode-DW junction. Furthermore, the activation energies needed to initiate the thermally activated electronic transport along the DWs can be extracted. In addition, we show that electronic transport along LNO DWs can be elegantly viewed and interpreted in an adapted semiconductor picture based on a double-diode, double-resistor equivalent-circuit model, the R2D2 model. Finally, our R2D2 model was checked for its universality by successfully fitting the I-U curves of not only z-cut LNO bulk DWs, but equally of z-cut thin-film LNO DWs, and of x-cut thin-film DWs as reported in literature.}},
  author       = {{Zahn, Manuel and Beyreuther, Elke and Kiseleva, Iuliia and Lotfy, Ahmed Samir and McCluskey, Conor J. and Maguire, Jesi R. and Suna, Ahmet and Rüsing, Michael and Gregg, J. Marty and Eng, Lukas M.}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  keywords     = {{General Physics and Astronomy}},
  number       = {{2}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Equivalent-circuit model that quantitatively describes domain-wall conductivity in ferroelectric lithium }}},
  doi          = {{10.1103/physrevapplied.21.024007}},
  volume       = {{21}},
  year         = {{2024}},
}

@article{55174,
  abstract     = {{<jats:p>We apply principal component analysis (PCA) to a set of electrical output signals from a commercially available superconducting nanowire single-photon detector (SNSPD) to investigate their photon-number-resolving capability. We find that the rising edge as well as the amplitude of the electrical signal have the most dependence on photon number. Accurately measuring the rising edge while simultaneously measuring the voltage of the pulse amplitude maximizes the photon-number resolution of SNSPDs. Using an optimal basis of principal components, we show unambiguous discrimination between one- and two-photon events, as well as partial resolution up to five photons. This expands the use case of SNSPDs to photon-counting experiments, without the need of detector multiplexing architectures.</jats:p>
          <jats:sec>
            <jats:title/>
            <jats:supplementary-material>
              <jats:permissions>
                <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement>
                <jats:copyright-year>2024</jats:copyright-year>
              </jats:permissions>
            </jats:supplementary-material>
          </jats:sec>}},
  author       = {{Schapeler, Timon and Lamberty, Niklas and Hummel, Thomas and Schlue, Fabian and Stefszky, Michael and Brecht, Benjamin and Silberhorn, Christine and Bartley, Tim}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  number       = {{1}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Electrical trace analysis of superconducting nanowire photon-number-resolving detectors}}},
  doi          = {{10.1103/physrevapplied.22.014024}},
  volume       = {{22}},
  year         = {{2024}},
}

@article{50407,
  abstract     = {{In the last decade, conductive domain walls (CDWs) in single crystals of the uniaxial model ferroelectric lithium niobate (LiNbO3; LNO) have been shown to reach resistances more than 10 orders of magnitude lower than the resistance of the surrounding bulk, with charge carriers being firmly confined to sheets with a width of a few nanometers. LNO is thus currently witnessing increased attention because of its potential in the design of room-temperature nanoelectronic circuits and devices based on such CDWs. In this context, the reliable determination of the fundamental transport parameters of LNO CDWs, in particular the 2D charge carrier density n2D and the Hall mobility μH of the majority carriers, is of great interest. In this contribution, we present and apply a robust and easy-to-prepare Hall-effect measurement setup by adapting the standard four-probe van der Pauw method to contact a single, hexagonally shaped domain wall that fully penetrates the 200-μm-thick LNO bulk single crystal. We then determine n2D and μH for a set of external magnetic fields B and prove the expected cosinelike angular dependence of the Hall voltage. Lastly, we present photoinduced-Hall-effect measurements of one and the same DW, by determining the impact of super-band-gap illumination on n2D.}},
  author       = {{Beccard, Henrik and Beyreuther, Elke and Kirbus, Benjamin and Seddon, Samuel D. and Rüsing, Michael and Eng, Lukas M.}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  keywords     = {{General Physics and Astronomy}},
  number       = {{6}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Hall mobilities and sheet carrier densities in a single LiNbO3 conductive ferroelectric domain wall}}},
  doi          = {{10.1103/physrevapplied.20.064043}},
  volume       = {{20}},
  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{30964,
  author       = {{Gao, Wenlong and Sain, Basudeb and Zentgraf, Thomas}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  keywords     = {{General Physics and Astronomy}},
  number       = {{4}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Spin-Orbit Interaction of Light Enabled by Negative Coupling in High-Quality-Factor Optical Metasurfaces}}},
  doi          = {{10.1103/physrevapplied.17.044022}},
  volume       = {{17}},
  year         = {{2022}},
}

@article{26221,
  author       = {{Bartnick, Moritz and Santandrea, Matteo and Höpker, Jan Philipp and Thiele, Frederik and Ricken, Raimund and Quiring, Viktor and Eigner, Christof and Herrmann, Harald and Silberhorn, Christine and Bartley, Tim}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  title        = {{{Cryogenic Second-Harmonic Generation in Periodically Poled Lithium Niobate Waveguides}}},
  doi          = {{10.1103/physrevapplied.15.024028}},
  year         = {{2021}},
}

@article{38046,
  author       = {{Faruque, Imad I. and Sinclair, Gary F. and Bonneau, Damien and Ono, Takafumi and Silberhorn, Christine and Thompson, Mark G. and Rarity, John G.}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  keywords     = {{General Physics and Astronomy}},
  number       = {{5}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Estimating the Indistinguishability of Heralded Single Photons Using Second-Order Correlation}}},
  doi          = {{10.1103/physrevapplied.12.054029}},
  volume       = {{12}},
  year         = {{2019}},
}

@article{63740,
  author       = {{Wright, Thomas A. and Francis-Jones, Robert J. A. and Gawith, Corin B. E. and Becker, Jonas N. and Ledingham, Patrick M. and Smith, Peter G. R. and Nunn, Joshua and Mosley, Peter J. and Brecht, Benjamin and Walmsley, Ian A.}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  number       = {{4}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Two-Way Photonic Interface for Linking the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:msup><mml:mi>Sr</mml:mi><mml:mo>+</mml:mo></mml:msup></mml:math> Transition at 422 nm to the Telecommunication <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:mi>C</mml:mi></mml:math> Band}}},
  doi          = {{10.1103/physrevapplied.10.044012}},
  volume       = {{10}},
  year         = {{2018}},
}

@article{26059,
  author       = {{Rütz, Helge and Luo, Kai Hong and Suche, Hubertus and Silberhorn, Christine}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  title        = {{{Quantum Frequency Conversion between Infrared and Ultraviolet}}},
  doi          = {{10.1103/physrevapplied.7.024021}},
  year         = {{2017}},
}

@article{4812,
  author       = {{Czerniuk, T. and Ehrlich, T. and Wecker, T. and As, Donat Josef and Yakovlev, D. R. and Akimov, A. V. and Bayer, M.}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  number       = {{1}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Picosecond Acoustics in Single Quantum Wells of Cubic GaN/(Al,Ga)N}}},
  doi          = {{10.1103/physrevapplied.7.014006}},
  volume       = {{7}},
  year         = {{2017}},
}

@article{9618,
  author       = {{Stefszky, Michael and Ricken, R. and Eigner, Christof and Quiring, V. and Herrmann, Harald and Silberhorn, Christine}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  title        = {{{Waveguide Cavity Resonator as a Source of Optical Squeezing}}},
  doi          = {{10.1103/physrevapplied.7.044026}},
  year         = {{2017}},
}

@article{9684,
  author       = {{Stefszky, M. and Ricken, R. and Eigner, Christof and Quiring, V. and Herrmann, Harald and Silberhorn, Christine}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  title        = {{{Waveguide Cavity Resonator as a Source of Optical Squeezing}}},
  doi          = {{10.1103/physrevapplied.7.044026}},
  year         = {{2017}},
}

@article{38058,
  author       = {{Montaut, Nicola and Sansoni, Linda and Meyer-Scott, Evan and Ricken, Raimund and Quiring, Viktor and Herrmann, Harald and Silberhorn, Christine}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  keywords     = {{General Physics and Astronomy}},
  number       = {{2}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{High-Efficiency Plug-and-Play Source of Heralded Single Photons}}},
  doi          = {{10.1103/physrevapplied.8.024021}},
  volume       = {{8}},
  year         = {{2017}},
}

@article{26040,
  author       = {{Stefszky, Michael and Ricken, R. and Eigner, Christof and Quiring, V. and Herrmann, Harald and Silberhorn, Christine}},
  issn         = {{2331-7019}},
  journal      = {{Physical Review Applied}},
  title        = {{{Waveguide Cavity Resonator as a Source of Optical Squeezing}}},
  doi          = {{10.1103/physrevapplied.7.044026}},
  year         = {{2017}},
}