@inproceedings{27160, abstract = {{We study the complexity of problems solvable in deterministic polynomial time with access to an NP or Quantum Merlin-Arthur (QMA)-oracle, such as $P^{NP}$ and $P^{QMA}$, respectively. The former allows one to classify problems more finely than the Polynomial-Time Hierarchy (PH), whereas the latter characterizes physically motivated problems such as Approximate Simulation (APX-SIM) [Ambainis, CCC 2014]. In this area, a central role has been played by the classes $P^{NP[\log]}$ and $P^{QMA[\log]}$, defined identically to $P^{NP}$ and $P^{QMA}$, except that only logarithmically many oracle queries are allowed. Here, [Gottlob, FOCS 1993] showed that if the adaptive queries made by a $P^{NP}$ machine have a "query graph" which is a tree, then this computation can be simulated in $P^{NP[\log]}$. In this work, we first show that for any verification class $C\in\{NP,MA,QCMA,QMA,QMA(2),NEXP,QMA_{\exp}\}$, any $P^C$ machine with a query graph of "separator number" $s$ can be simulated using deterministic time $\exp(s\log n)$ and $s\log n$ queries to a $C$-oracle. When $s\in O(1)$ (which includes the case of $O(1)$-treewidth, and thus also of trees), this gives an upper bound of $P^{C[\log]}$, and when $s\in O(\log^k(n))$, this yields bound $QP^{C[\log^{k+1}]}$ (QP meaning quasi-polynomial time). We next show how to combine Gottlob's "admissible-weighting function" framework with the "flag-qubit" framework of [Watson, Bausch, Gharibian, 2020], obtaining a unified approach for embedding $P^C$ computations directly into APX-SIM instances in a black-box fashion. Finally, we formalize a simple no-go statement about polynomials (c.f. [Krentel, STOC 1986]): Given a multi-linear polynomial $p$ specified via an arithmetic circuit, if one can "weakly compress" $p$ so that its optimal value requires $m$ bits to represent, then $P^{NP}$ can be decided with only $m$ queries to an NP-oracle.}}, author = {{Gharibian, Sevag and Rudolph, Dorian}}, booktitle = {{13th Innovations in Theoretical Computer Science (ITCS 2022)}}, number = {{75}}, pages = {{1--27}}, title = {{{On polynomially many queries to NP or QMA oracles}}}, doi = {{10.4230/LIPIcs.ITCS.2022.75}}, volume = {{215}}, year = {{2022}}, } @article{21631, abstract = {{Secret sharing is a well-established cryptographic primitive for storing highly sensitive information like encryption keys for encoded data. It describes the problem of splitting a secret into different shares, without revealing any information to its shareholders. Here, we demonstrate an all-optical solution for secret sharing based on metasurface holography. In our concept, metasurface holograms are used as spatially separable shares that carry encrypted messages in the form of holographic images. Two of these shares can be recombined by bringing them close together. Light passing through this stack of metasurfaces accumulates the phase shift of both holograms and optically reconstructs the secret with high fidelity. In addition, the hologram generated by each single metasurface can uniquely identify its shareholder. Furthermore, we demonstrate that the inherent translational alignment sensitivity between two stacked metasurface holograms can be used for spatial multiplexing, which can be further extended to realize optical rulers.}}, author = {{Georgi, Philip and Wei, Qunshuo and Sain, Basudeb and Schlickriede, Christian and Wang, Yongtian and Huang, Lingling and Zentgraf, Thomas}}, issn = {{2375-2548}}, journal = {{Science Advances}}, number = {{16}}, title = {{{Optical secret sharing with cascaded metasurface holography}}}, doi = {{10.1126/sciadv.abf9718}}, volume = {{7}}, year = {{2021}}, } @article{28255, abstract = {{Topological photonic crystals (TPhCs) provide robust manipulation of light with built-in immunity to fabrication tolerances and disorder. Recently, it was shown that TPhCs based on weak topology with a dislocation inherit this robustness and further host topologically protected lower-dimensional localized modes. However, TPhCs with weak topology at optical frequencies have not been demonstrated so far. Here, we use scattering-type scanning near-field optical microscopy to verify mid-bandgap zero-dimensional light localization close to 100 THz in a TPhC with nontrivial Zak phase and an edge dislocation. We show that because of the weak topology, differently extended dislocation centers induce similarly strong light localization. The experimental results are supported by full-field simulations. Along with the underlying fundamental physics, our results lay a foundation for the application of TPhCs based on weak topology in active topological nanophotonics, and nonlinear and quantum optic integrated devices because of their strong and robust light localization.}}, author = {{Lu, Jinlong and Wirth, Konstantin G. and Gao, Wenlong and Heßler, Andreas and Sain, Basudeb and Taubner, Thomas and Zentgraf, Thomas}}, issn = {{2375-2548}}, journal = {{Science Advances}}, number = {{49}}, title = {{{Observing 0D subwavelength-localized modes at ~100 THz protected by weak topology}}}, doi = {{10.1126/sciadv.abl3903}}, volume = {{7}}, year = {{2021}}, } @article{31261, abstract = {{Abstract For a compact Riemannian locally symmetric space $\mathcal M$ of rank 1 and an associated vector bundle $\mathbf V_{\tau }$ over the unit cosphere bundle $S^{\ast }\mathcal M$, we give a precise description of those classical (Pollicott–Ruelle) resonant states on $\mathbf V_{\tau }$ that vanish under covariant derivatives in the Anosov-unstable directions of the chaotic geodesic flow on $S^{\ast }\mathcal M$. In particular, we show that they are isomorphically mapped by natural pushforwards into generalized common eigenspaces of the algebra of invariant differential operators $D(G,\sigma )$ on compatible associated vector bundles $\mathbf W_{\sigma }$ over $\mathcal M$. As a consequence of this description, we obtain an exact band structure of the Pollicott–Ruelle spectrum. Further, under some mild assumptions on the representations $\tau$ and $\sigma$ defining the bundles $\mathbf V_{\tau }$ and $\mathbf W_{\sigma }$, we obtain a very explicit description of the generalized common eigenspaces. This allows us to relate classical Pollicott–Ruelle resonances to quantum eigenvalues of a Laplacian in a suitable Hilbert space of sections of $\mathbf W_{\sigma }$. Our methods of proof are based on representation theory and Lie theory.}}, author = {{Küster, Benjamin and Weich, Tobias}}, issn = {{1073-7928}}, journal = {{International Mathematics Research Notices}}, keywords = {{General Mathematics}}, number = {{11}}, pages = {{8225--8296}}, publisher = {{Oxford University Press (OUP)}}, title = {{{Quantum-Classical Correspondence on Associated Vector Bundles Over Locally Symmetric Spaces}}}, doi = {{10.1093/imrn/rnz068}}, volume = {{2021}}, year = {{2021}}, } @article{29524, author = {{De, Syamsundar and Gil López, Jano and Brecht, Benjamin and Silberhorn, Christine and Sánchez-Soto, Luis L. and Hradil, Zdeněk and Řeháček, Jaroslav}}, issn = {{2643-1564}}, journal = {{Physical Review Research}}, keywords = {{General Engineering}}, number = {{3}}, publisher = {{American Physical Society (APS)}}, title = {{{Effects of coherence on temporal resolution}}}, doi = {{10.1103/physrevresearch.3.033082}}, volume = {{3}}, year = {{2021}}, } @article{22259, author = {{Roman-Rodriguez, V and Brecht, Benjamin and Srinivasan, K and Silberhorn, Christine and Treps, N and Diamanti, E and Parigi, V}}, issn = {{1367-2630}}, journal = {{New Journal of Physics}}, title = {{{Continuous variable multimode quantum states via symmetric group velocity matching}}}, doi = {{10.1088/1367-2630/abef96}}, volume = {{23}}, year = {{2021}}, } @article{31263, author = {{Guillarmou, Colin and Hilgert, Joachim and Weich, Tobias}}, issn = {{2644-9463}}, journal = {{Annales Henri Lebesgue}}, pages = {{81--119}}, publisher = {{Cellule MathDoc/CEDRAM}}, title = {{{High frequency limits for invariant Ruelle densities}}}, doi = {{10.5802/ahl.67}}, volume = {{4}}, year = {{2021}}, } @misc{38135, author = {{Padberg, Laura and Eigner, Christof and Santandrea, Matteo and Silberhorn, Christine}}, title = {{{Production of waveguides made of materials from the KTP family}}}, year = {{2021}}, } @article{37936, author = {{Pelucchi, Emanuele and Fagas, Giorgos and Aharonovich, Igor and Englund, Dirk and Figueroa, Eden and Gong, Qihuang and Hannes, Hübel and Liu, Jin and Lu, Chao-Yang and Matsuda, Nobuyuki and Pan, Jian-Wei and Schreck, Florian and Sciarrino, Fabio and Silberhorn, Christine and Wang, Jianwei and Jöns, Klaus}}, issn = {{2522-5820}}, journal = {{Nature Reviews Physics}}, keywords = {{General Physics and Astronomy}}, number = {{3}}, pages = {{194--208}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{The potential and global outlook of integrated photonics for quantum technologies}}}, doi = {{10.1038/s42254-021-00398-z}}, volume = {{4}}, year = {{2021}}, } @article{22770, author = {{Gil López, Jano and Santandrea, Matteo and Roland, Ganaël and Brecht, Benjamin and Eigner, Christof and Ricken, Raimund and Quiring, Viktor and Silberhorn, Christine}}, issn = {{1367-2630}}, journal = {{New Journal of Physics}}, title = {{{Improved non-linear devices for quantum applications}}}, doi = {{10.1088/1367-2630/ac09fd}}, year = {{2021}}, } @article{26410, author = {{Gil López, Jano and Teo, Yong Siah and De, Syamsundar and Brecht, Benjamin and Jeong, Hyunseok and Silberhorn, Christine and Sánchez-Soto, Luis L.}}, issn = {{2334-2536}}, journal = {{Optica}}, title = {{{Universal compressive tomography in the time-frequency domain}}}, doi = {{10.1364/optica.427645}}, year = {{2021}}, } @inproceedings{41890, author = {{Gyger, S and Zichi, J and Schweickert, L and Elshaari, A.W and Steinhauer, S and Covre da Silva, S.F and Rastelli, A and Zwiller, V and Jöns, Klaus D. and Errando-Herranz, C}}, pages = {{1408}}, title = {{{Reconfigurable quantum photonics with on-chip detectors}}}, volume = {{12}}, year = {{2021}}, } @inproceedings{41891, author = {{Klein, J and Sigl, L and Gyger, S and Barthelmi, K and Florian, M and Rey, S and Taniguchi, T and Watanabe, K and Jahnke, F and Kastl, C and Zwiller, V and Jöns, Klaus D. and Müller, K and Wurstbauer, U and Finley, J.F and Holleitner, A.W}}, number = {{1}}, pages = {{669--677}}, title = {{{ Engineering the Luminescence and Generation of Individual Defect Emitters in Atomically Thin MoS2}}}, volume = {{8}}, year = {{2021}}, } @inproceedings{41888, author = {{Schimpf, C and Reindl, M and Basset, F.B and Jöns, Klaus D. and Trotta, R and Rastelli, A}}, number = {{10}}, title = {{{Quantum dots as potential sources of strongly entangled photons: Perspectives and challenges for applications in quantum networks}}}, volume = {{118}}, year = {{2021}}, } @inproceedings{41893, author = {{Hötger, A and Klein, J and Barthelmi, K and Sigl, L and Sigger, F and Männer, W and Gyger, S and Florian, M and Lorke, M and Jahnke, F and Taniguchi, T and Watanabe, K and Jöns, Klaus D. and Wurstbauer, U and Kastl, C and Müller, K and J. J. Finley, J.J and A. W. Holleitner, A.W}}, number = {{2}}, pages = {{1040--1046}}, title = {{{Gate-Switchable Arrays of Quantum Light Emitters in Contacted Monolayer MoS2 van der Waals Heterodevices}}}, volume = {{21}}, year = {{2021}}, } @inproceedings{41882, author = {{Neuwirth, J and Basso Basset, F and Rota, M. B and Roccia, E and Schimpf, C and Jöns, Klaus D. and Rastelli, A and Trotta, R}}, number = {{4}}, title = {{{Quantum dot technology for quantum repeaters: from entangled photon generation toward the integration with quantum memories}}}, volume = {{1}}, year = {{2021}}, } @inproceedings{41887, author = {{Wang, Y and Jöns, Klaus D. and Sun, Z}}, number = {{1}}, title = {{{Integrated photon-pair sources with nonlinear optics}}}, volume = {{8}}, year = {{2021}}, } @inproceedings{41886, author = {{Tuktamyshev, A and Fedorov, A and Bietti, S and Vichi, S and Zeuner, K.D and Jöns, Klaus D. and Chrastina, D and Tsukamoto, S and Zwiller, V and Gurioli, M and Sanguinetti, S}}, number = {{13}}, title = {{{Telecom-wavelength InAs QDs with low fine structure splitting grown by droplet epitaxy on GaAs (111) A vicinal substrates}}}, volume = {{118}}, year = {{2021}}, } @inproceedings{41885, author = {{Errando-Herranz, C and Schöll, E and Picard, R and Laini, M and Gyger, S and Elshaari, A.W and Branny, A and Wennberg, U and Barbat, S and Renaud, T and Brotons-Gisbert, M and Bonato, C and Gerardot, B.D and Zwiller, V and Jöns, Klaus D.}}, number = {{4}}, pages = {{1069–1076 }}, title = {{{Resonance fluorescence from waveguide–coupled, strain–localized two–dimensional quantum emitters}}}, volume = {{8}}, year = {{2021}}, } @inproceedings{41884, author = {{Jöns, Klaus D. and Zeuner, K.D and Schweickert, L and Hedlund, C.R and Lobato, C.N and Lettner, T and Wang, K and Gyger, S and Schöll, E and Steinhauer, S and Hammar, M and Zwiller, V}}, pages = {{2337–2344 }}, title = {{{On-Demand Generation of Entangled Photon Pairs in the Telecom C-Band with InAs Quantum Dots}}}, volume = {{88}}, year = {{2021}}, }