@article{55737,
abstract = {{We report on a photonic simulator of the critical state forming at the quantum phase transition between topologically distinct Anderson insulator phases. We observe a time-staggered profile in the circular photon polarization, which originates from the interplay of a chiral and sublattice symmetry, and has recently been suggested as a signature for topological Anderson criticality within the setup. We discuss the role of statistical detuning from criticality and show that the controlled breaking of phase coherence removes the signal, revealing its origin in quantum coherence.
Published by the American Physical Society
2024
}},
author = {{Barkhofen, Sonja and De, Syamsundar and Sperling, Jan and Silberhorn, Christine and Altland, Alexander and Bagrets, Dmitry and Kim, Kun Woo and Micklitz, Tobias}},
issn = {{2643-1564}},
journal = {{Physical Review Research}},
number = {{3}},
publisher = {{American Physical Society (APS)}},
title = {{{Experimental observation of topological quantum criticality}}},
doi = {{10.1103/physrevresearch.6.033194}},
volume = {{6}},
year = {{2024}},
}
@article{52876,
author = {{Arends, Christian and Wolf, Lasse Lennart and Meinecke, Jasmin and Barkhofen, Sonja and Weich, Tobias and Bartley, Tim}},
issn = {{2643-1564}},
journal = {{Physical Review Research}},
keywords = {{General Physics and Astronomy}},
number = {{1}},
publisher = {{American Physical Society (APS)}},
title = {{{Decomposing large unitaries into multimode devices of arbitrary size}}},
doi = {{10.1103/physrevresearch.6.l012043}},
volume = {{6}},
year = {{2024}},
}
@article{54288,
abstract = {{The ability to apply user-chosen large-scale unitary operations with high fidelity to a quantum state is key to realizing future photonic quantum technologies. Here, we realize the implementation of programmable unitary operations on up to 64 frequency-bin modes. To benchmark the performance of our system, we probe different quantum walk unitary operations, in particular, Grover walks on four-dimensional hypercubes with similarities exceeding 95% and quantum walks with 400 steps on circles and finite lines with similarities of 98%. Our results open a path toward implementing high-quality unitary operations, which can form the basis for applications in complex tasks, such as Gaussian boson sampling.
Published by the American Physical Society
2024
}},
author = {{De, Syamsundar and Ansari, Vahid and Sperling, Jan and Barkhofen, Sonja and Brecht, Benjamin and Silberhorn, Christine}},
issn = {{2643-1564}},
journal = {{Physical Review Research}},
number = {{2}},
publisher = {{American Physical Society (APS)}},
title = {{{Realization of high-fidelity unitary operations on up to 64 frequency bins}}},
doi = {{10.1103/physrevresearch.6.l022040}},
volume = {{6}},
year = {{2024}},
}
@article{31059,
abstract = {{In this article we prove meromorphic continuation of weighted zeta functions in the framework of open hyperbolic systems by using the meromorphically continued restricted resolvent of Dyatlov and Guillarmou (2016). We obtain a residue formula proving equality between residues of weighted zetas and invariant Ruelle distributions. We combine this equality with results of Guillarmou, Hilgert and Weich (2021) in order to relate the residues to Patterson-Sullivan distributions. Finally we provide proof-of-principle results concerning the numerical calculation of invariant Ruelle distributions for 3-disc scattering systems.}},
author = {{Schütte, Philipp and Weich, Tobias and Barkhofen, Sonja}},
journal = {{Communications in Mathematical Physics}},
pages = {{655--678}},
title = {{{Meromorphic Continuation of Weighted Zeta Functions on Open Hyperbolic Systems}}},
doi = {{https://doi.org/10.1007/s00220-022-04538-z}},
volume = {{398}},
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}},
}
@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}},
}
@article{31057,
abstract = {{In this paper we give an overview over some aspects of the modern mathematical theory of Ruelle resonances for chaotic, i.e. uniformly hyperbolic, dynamical systems and their implications in physics. First we recall recent developments in the mathematical theory of resonances, in particular how invariant Ruelle distributions arise as residues of weighted zeta functions. Then we derive a correspondence between weighted and semiclassical zeta functions in the setting of negatively curved surfaces. Combining this with results of Hilgert, Guillarmou and Weich yields a high frequency interpretation of invariant Ruelle distributions as quantum mechanical matrix coefficients in constant negative curvature. We finish by presenting numerical calculations of phase space distributions in the more physical setting of 3-disk scattering systems.}},
author = {{Barkhofen, Sonja and Schütte, Philipp and Weich, Tobias}},
journal = {{Journal of Physics A: Mathematical and Theoretical}},
number = {{24}},
publisher = {{IOP Publishing Ltd}},
title = {{{Semiclassical formulae For Wigner distributions}}},
doi = {{10.1088/1751-8121/ac6d2b}},
volume = {{55}},
year = {{2022}},
}
@article{39025,
author = {{Meyer-Scott, Evan and Prasannan, Nidhin and Dhand, Ish and Eigner, Christof and Quiring, Viktor and Barkhofen, Sonja and Brecht, Benjamin and Plenio, Martin B. and Silberhorn, Christine}},
issn = {{0031-9007}},
journal = {{Physical Review Letters}},
keywords = {{General Physics and Astronomy}},
number = {{15}},
publisher = {{American Physical Society (APS)}},
title = {{{Scalable Generation of Multiphoton Entangled States by Active Feed-Forward and Multiplexing}}},
doi = {{10.1103/physrevlett.129.150501}},
volume = {{129}},
year = {{2022}},
}
@article{40273,
author = {{Meyer-Scott, Evan and Prasannan, Nidhin and Dhand, Ish and Eigner, Christof and Quiring, Viktor and Barkhofen, Sonja and Brecht, Benjamin and Plenio, Martin B. and Silberhorn, Christine}},
issn = {{0031-9007}},
journal = {{Physical Review Letters}},
keywords = {{General Physics and Astronomy}},
number = {{15}},
publisher = {{American Physical Society (APS)}},
title = {{{Scalable Generation of Multiphoton Entangled States by Active Feed-Forward and Multiplexing}}},
doi = {{10.1103/physrevlett.129.150501}},
volume = {{129}},
year = {{2022}},
}
@article{33450,
author = {{Hamilton, Craig S. and Christ, Regina and Barkhofen, Sonja and Barnett, Stephen M. and Jex, Igor and Silberhorn, Christine}},
issn = {{2469-9926}},
journal = {{Physical Review A}},
number = {{4}},
publisher = {{American Physical Society (APS)}},
title = {{{Quantum-state creation in nonlinear-waveguide arrays}}},
doi = {{10.1103/physreva.105.042622}},
volume = {{105}},
year = {{2022}},
}
@article{30921,
abstract = {{Quantum walks function as essential means to implement quantum simulators, allowing one to study complex and often directly inaccessible quantum processes in controllable systems. In this contribution, the notion of a driven Gaussian quantum walk is introduced. In contrast to typically considered quantum walks in optical settings, we describe the operation of the walk in terms of a nonlinear map rather than a unitary operation, e.g., by replacing a beam-splitter-type coin with a two-mode squeezer, being a process that is controlled and driven by a pump field. This opens previously unattainable possibilities for quantum walks that include nonlinear elements as core components of their operation, vastly extending their range of applications. A full framework for driven Gaussian quantum walks is developed, including methods to dynamically characterize nonlinear, quantum, and quantum-nonlinear effects. Moreover, driven Gaussian quantum walks are compared with their classically interfering and linear counterparts, which are based on classical coherence of light rather than quantum superpositions. In particular, the generation and boost of highly multimode entanglement, squeezing, and other quantum effects are studied over the duration of the nonlinear walk. Importantly, we prove the quantumness of the evolution itself, regardless of the input state. A scheme for an experimental realization is proposed. Furthermore, nonlinear properties of driven Gaussian quantum walks are explored, such as amplification that leads to an ever increasing number of correlated quantum particles, constituting a source of new walkers during the walk. Therefore, a concept for quantum walks is proposed that leads to—and even produces—directly accessible quantum phenomena, and that renders the quantum simulation of nonlinear processes possible.}},
author = {{Held, Philip and Engelkemeier, Melanie and De, Syamsundar and Barkhofen, Sonja and Sperling, Jan and Silberhorn, Christine}},
issn = {{2469-9926}},
journal = {{Physical Review A}},
number = {{4}},
publisher = {{American Physical Society (APS)}},
title = {{{Driven Gaussian quantum walks}}},
doi = {{10.1103/physreva.105.042210}},
volume = {{105}},
year = {{2022}},
}
@article{26284,
author = {{Bagrets, Dmitry and Kim, Kun Woo and Barkhofen, Sonja and De, Syamsundar and Sperling, Jan and Silberhorn, Christine and Altland, Alexander and Micklitz, Tobias}},
issn = {{2643-1564}},
journal = {{Physical Review Research}},
title = {{{Probing the topological Anderson transition with quantum walks}}},
doi = {{10.1103/physrevresearch.3.023183}},
year = {{2021}},
}
@article{26287,
author = {{Geraldi, Andrea and De, Syamsundar and Laneve, Alessandro and Barkhofen, Sonja and Sperling, Jan and Mataloni, Paolo and Silberhorn, Christine}},
issn = {{2643-1564}},
journal = {{Physical Review Research}},
title = {{{Transient subdiffusion via disordered quantum walks}}},
doi = {{10.1103/physrevresearch.3.023052}},
year = {{2021}},
}
@article{26286,
author = {{Prasannan, Nidhin and De, Syamsundar and Barkhofen, Sonja and Brecht, Benjamin and Silberhorn, Christine and Sperling, Jan}},
issn = {{2469-9926}},
journal = {{Physical Review A}},
title = {{{Experimental entanglement characterization of two-rebit states}}},
doi = {{10.1103/physreva.103.l040402}},
volume = {{103}},
year = {{2021}},
}
@article{26507,
author = {{Smirne, A and Nitsche, T and Egloff, D and Barkhofen, Sonja and De, S and Dhand, I and Silberhorn, Christine and Huelga, S F and Plenio, M B}},
issn = {{2058-9565}},
journal = {{Quantum Science and Technology}},
title = {{{Experimental control of the degree of non-classicality via quantum coherence}}},
doi = {{10.1088/2058-9565/aba039}},
year = {{2020}},
}
@article{26289,
author = {{Nitsche, Thomas and De, Syamsundar and Barkhofen, Sonja and Meyer-Scott, Evan and Tiedau, Johannes and Sperling, Jan and Gábris, Aurél and Jex, Igor and Silberhorn, Christine}},
issn = {{0031-9007}},
journal = {{Physical Review Letters}},
title = {{{Local Versus Global Two-Photon Interference in Quantum Networks}}},
doi = {{10.1103/physrevlett.125.213604}},
year = {{2020}},
}
@article{26500,
author = {{Lorz, Lennart and Meyer-Scott, Evan and Nitsche, Thomas and Potoček, Václav and Gábris, Aurél and Barkhofen, Sonja and Jex, Igor and Silberhorn, Christine}},
issn = {{2643-1564}},
journal = {{Physical Review Research}},
title = {{{Photonic quantum walks with four-dimensional coins}}},
doi = {{10.1103/physrevresearch.1.033036}},
year = {{2019}},
}
@article{26501,
author = {{Kruse, Regina and Hamilton, Craig S. and Sansoni, Linda and Barkhofen, Sonja and Silberhorn, Christine and Jex, Igor}},
issn = {{2469-9926}},
journal = {{Physical Review A}},
title = {{{Detailed study of Gaussian boson sampling}}},
doi = {{10.1103/physreva.100.032326}},
year = {{2019}},
}
@article{26508,
author = {{Nitsche, Thomas and Geib, Tobias and Stahl, Christoph and Lorz, Lennart and Cedzich, Christopher and Barkhofen, Sonja and Werner, Reinhard F and Silberhorn, Christine}},
issn = {{1367-2630}},
journal = {{New Journal of Physics}},
title = {{{Eigenvalue measurement of topologically protected edge states in split-step quantum walks}}},
doi = {{10.1088/1367-2630/ab12fa}},
year = {{2019}},
}
@article{26509,
author = {{Tiedau, Johannes and Meyer-Scott, Evan and Nitsche, Thomas and Barkhofen, Sonja and Bartley, Tim J. and Silberhorn, Christine}},
issn = {{1094-4087}},
journal = {{Optics Express}},
title = {{{A high dynamic range optical detector for measuring single photons and bright light}}},
doi = {{10.1364/oe.27.000001}},
year = {{2019}},
}