@article{7509,
  abstract     = {In this paper we study the joint convexity/concavity of the trace functions Ψp,q,s(A,B)=Tr(Bq2K∗ApKBq2)s,  p,q,s∈R,
where A and B are positive definite matrices and K is any fixed invertible matrix. We will give full range of (p,q,s)∈R3 for Ψp,q,s to be jointly convex/concave for all K. As a consequence, we confirm a conjecture of Carlen, Frank and Lieb. In particular, we confirm a weaker conjecture of Audenaert and Datta and obtain the full range of (α,z) for α-z Rényi relative entropies to be monotone under completely positive trace preserving maps. We also give simpler proofs of many known results, including the concavity of Ψp,0,1/p for 0<p<1 which was first proved by Epstein using complex analysis. The key is to reduce the problem to the joint convexity/concavity of the trace functions Ψp,1−p,1(A,B)=TrK∗ApKB1−p,  −1≤p≤1, using a variational method. },
  author       = {Zhang, Haonan},
  journal      = {Advances in Mathematics},
  publisher    = {Elsevier},
  title        = {{From Wigner-Yanase-Dyson conjecture to Carlen-Frank-Lieb conjecture}},
  doi          = {10.1016/j.aim.2020.107053},
  volume       = {365},
  year         = {2020},
}

@article{7511,
  abstract     = {Cryo electron tomography with subsequent subtomogram averaging is a powerful technique to structurally analyze macromolecular complexes in their native context. Although close to atomic resolution in principle can be obtained, it is not clear how individual experimental parameters contribute to the attainable resolution. Here, we have used immature HIV-1 lattice as a benchmarking sample to optimize the attainable resolution for subtomogram averaging. We systematically tested various experimental parameters such as the order of projections, different angular increments and the use of the Volta phase plate. We find that although any of the prominently used acquisition schemes is sufficient to obtain subnanometer resolution, dose-symmetric acquisition provides considerably better outcome. We discuss our findings in order to provide guidance for data acquisition. Our data is publicly available and might be used to further develop processing routines.},
  author       = {Turoňová, Beata and Hagen, Wim J.H. and Obr, Martin and Mosalaganti, Shyamal and Beugelink, J. Wouter and Zimmerli, Christian E. and Kräusslich, Hans Georg and Beck, Martin},
  issn         = {2041-1723},
  journal      = {Nature Communications},
  publisher    = {Springer Nature},
  title        = {{Benchmarking tomographic acquisition schemes for high-resolution structural biology}},
  doi          = {10.1038/s41467-020-14535-2},
  volume       = {11},
  year         = {2020},
}

@article{7512,
  abstract     = {We consider general self-adjoint polynomials in several independent random matrices whose entries are centered and have the same variance. We show that under certain conditions the local law holds up to the optimal scale, i.e., the eigenvalue density on scales just above the eigenvalue spacing follows the global density of states which is determined by free probability theory. We prove that these conditions hold for general homogeneous polynomials of degree two and for symmetrized products of independent matrices with i.i.d. entries, thus establishing the optimal bulk local law for these classes of ensembles. In particular, we generalize a similar result of Anderson for anticommutator. For more general polynomials our conditions are effectively checkable numerically.},
  author       = {Erdös, László and Krüger, Torben H and Nemish, Yuriy},
  issn         = {1096-0783},
  journal      = {Journal of Functional Analysis},
  number       = {12},
  publisher    = {Elsevier},
  title        = {{Local laws for polynomials of Wigner matrices}},
  doi          = {10.1016/j.jfa.2020.108507},
  volume       = {278},
  year         = {2020},
}

@phdthesis{7514,
  abstract     = {We study the interacting homogeneous Bose gas in two spatial dimensions in the thermodynamic limit at fixed density. We shall be concerned with some mathematical aspects of this complicated problem in many-body quantum mechanics. More specifically, we consider the dilute limit where the scattering length of the interaction potential, which is a measure for the effective range of the potential, is small compared to the average distance between the particles. We are interested in a setting with positive (i.e., non-zero) temperature. After giving a survey of the relevant literature in the field, we provide some facts and examples to set expectations for the two-dimensional system. The crucial difference to the three-dimensional system is that there is no Bose–Einstein condensate at positive temperature due to the Hohenberg–Mermin–Wagner theorem. However, it turns out that an asymptotic formula for the free energy holds similarly to the three-dimensional case.
We motivate this formula by considering a toy model with δ interaction potential. By restricting this model Hamiltonian to certain trial states with a quasi-condensate we obtain an upper bound for the free energy that still has the quasi-condensate fraction as a free parameter. When minimizing over the quasi-condensate fraction, we obtain the Berezinskii–Kosterlitz–Thouless critical temperature for superfluidity, which plays an important role in our rigorous contribution. The mathematically rigorous result that we prove concerns the specific free energy in the dilute limit. We give upper and lower bounds on the free energy in terms of the free energy of the non-interacting system and a correction term coming from the interaction. Both bounds match and thus we obtain the leading term of an asymptotic approximation in the dilute limit, provided the thermal wavelength of the particles is of the same order (or larger) than the average distance between the particles. The remarkable feature of this result is its generality: the correction term depends on the interaction potential only through its scattering length and it holds for all nonnegative interaction potentials with finite scattering length that are measurable. In particular, this allows to model an interaction of hard disks.},
  author       = {Mayer, Simon},
  issn         = {2663-337X},
  pages        = {148},
  publisher    = {Institute of Science and Technology Austria},
  title        = {{The free energy of a dilute two-dimensional Bose gas}},
  doi          = {10.15479/AT:ISTA:7514},
  year         = {2020},
}

@article{7534,
  abstract     = {In the past two decades, our understanding of the transition to turbulence in shear flows with linearly stable laminar solutions has greatly improved. Regarding the susceptibility of the laminar flow, two concepts have been particularly useful: the edge states and the minimal seeds. In this nonlinear picture of the transition, the basin boundary of turbulence is set by the edge state's stable manifold and this manifold comes closest in energy to the laminar equilibrium at the minimal seed. We begin this paper by presenting numerical experiments in which three-dimensional perturbations are too energetic to trigger turbulence in pipe flow but they do lead to turbulence when their amplitude is reduced. We show that this seemingly counterintuitive observation is in fact consistent with the fully nonlinear description of the transition mediated by the edge state. In order to understand the physical mechanisms behind this process, we measure the turbulent kinetic energy production and dissipation rates as a function of the radial coordinate. Our main observation is that the transition to turbulence relies on the energy amplification away from the wall, as opposed to the turbulence itself, whose energy is predominantly produced near the wall. This observation is further supported by the similar analyses on the minimal seeds and the edge states. Furthermore, we show that the time evolution of production-over-dissipation curves provides a clear distinction between the different initial amplification stages of the transition to turbulence from the minimal seed.},
  author       = {Budanur, Nazmi B and Marensi, Elena and Willis, Ashley P. and Hof, Björn},
  issn         = {2469-990X},
  journal      = {Physical Review Fluids},
  number       = {2},
  publisher    = {American Physical Society},
  title        = {{Upper edge of chaos and the energetics of transition in pipe flow}},
  doi          = {10.1103/physrevfluids.5.023903},
  volume       = {5},
  year         = {2020},
}

@article{7540,
  abstract     = { In vitro propagation of the ornamentally interesting species Wikstroemia gemmata is limited by the recalcitrance to form adventitious roots. In this article, two strategies to improve the rooting capacity of in vitro microcuttings are presented. Firstly, the effect of exogenous auxin was evaluated in both light and dark cultivated stem segments and also the sucrose-content of the medium was varied in order to determine better rooting conditions. Secondly, different spectral lights were evaluated and the effect on shoot growth and root induction demonstrated that the exact spectral composition of light is important for successful in vitro growth and development of Wikstroemia gemmata. We show that exogenous auxin cannot compensate for the poor rooting under unfavorable light conditions. Adapting the culture conditions is therefore paramount for successful industrial propagation of Wikstroemia gemmata. },
  author       = {Verstraeten, Inge and Buyle, H. and Werbrouck, S. and Van Labeke, M.C. and Geelen, D.},
  issn         = {2223-8980},
  journal      = {Israel Journal of Plant Sciences},
  number       = {1-2},
  pages        = {16--26},
  publisher    = {Brill},
  title        = {{In vitro shoot growth and adventitious rooting of Wikstroemia gemmata depends on light quality}},
  doi          = {10.1163/22238980-20191110},
  volume       = {67},
  year         = {2020},
}

@article{7541,
  abstract     = {Semiconductor nanowires have been playing a crucial role in the development of nanoscale devices for the realization of spin qubits, Majorana fermions, single photon emitters, nanoprocessors, etc. The monolithic growth of site‐controlled nanowires is a prerequisite toward the next generation of devices that will require addressability and scalability. Here, combining top‐down nanofabrication and bottom‐up self‐assembly, the growth of Ge wires on prepatterned Si (001) substrates with controllable position, distance, length, and structure is reported. This is achieved by a novel growth process that uses a SiGe strain‐relaxation template and can be potentially generalized to other material combinations. Transport measurements show an electrically tunable spin–orbit coupling, with a spin–orbit length similar to that of III–V materials. Also, charge sensing between quantum dots in closely spaced wires is observed, which underlines their potential for the realization of advanced quantum devices. The reported results open a path toward scalable qubit devices using nanowires on silicon.},
  author       = {Gao, Fei and Wang, Jian-Huan and Watzinger, Hannes and Hu, Hao and Rančić, Marko J. and Zhang, Jie-Yin and Wang, Ting and Yao, Yuan and Wang, Gui-Lei and Kukucka, Josip and Vukušić, Lada and Kloeffel, Christoph and Loss, Daniel and Liu, Feng and Katsaros, Georgios and Zhang, Jian-Jun},
  issn         = {0935-9648},
  journal      = {Advanced Materials},
  number       = {16},
  publisher    = {Wiley},
  title        = {{Site-controlled uniform Ge/Si hut wires with electrically tunable spin-orbit coupling}},
  doi          = {10.1002/adma.201906523},
  volume       = {32},
  year         = {2020},
}

@article{7546,
  abstract     = {The extent to which behavior is shaped by experience varies between individuals. Genetic differences contribute to this variation, but the neural mechanisms are not understood. Here, we dissect natural variation in the behavioral flexibility of two Caenorhabditis elegans wild strains. In one strain, a memory of exposure to 21% O2 suppresses CO2-evoked locomotory arousal; in the other, CO2 evokes arousal regardless of previous O2 experience. We map that variation to a polymorphic dendritic scaffold protein, ARCP-1, expressed in sensory neurons. ARCP-1 binds the Ca2+-dependent phosphodiesterase PDE-1 and co-localizes PDE-1 with molecular sensors for CO2 at dendritic ends. Reducing ARCP-1 or PDE-1 activity promotes CO2 escape by altering neuropeptide expression in the BAG CO2 sensors. Variation in ARCP-1 alters behavioral plasticity in multiple paradigms. Our findings are reminiscent of genetic accommodation, an evolutionary process by which phenotypic flexibility in response to environmental variation is reset by genetic change.},
  author       = {Beets, Isabel and Zhang, Gaotian and Fenk, Lorenz A. and Chen, Changchun and Nelson, Geoffrey M. and Félix, Marie-Anne and de Bono, Mario},
  issn         = {0896-6273},
  journal      = {Neuron},
  number       = {1},
  pages        = {106--121.e10},
  publisher    = {Cell Press},
  title        = {{Natural variation in a dendritic scaffold protein remodels experience-dependent plasticity by altering neuropeptide expression}},
  doi          = {10.1016/j.neuron.2019.10.001},
  volume       = {105},
  year         = {2020},
}

@article{7554,
  abstract     = {Slicing a Voronoi tessellation in ${R}^n$ with a $k$-plane gives a $k$-dimensional weighted Voronoi tessellation, also known as a power diagram or Laguerre tessellation. Mapping every simplex of the dual weighted Delaunay mosaic to the radius of the smallest empty circumscribed sphere whose center lies in the $k$-plane gives a generalized discrete Morse function. Assuming the Voronoi tessellation is generated by a Poisson point process in ${R}^n$, we study the expected number of simplices in the $k$-dimensional weighted Delaunay mosaic as well as the expected number of intervals of the Morse function, both as functions of a radius threshold. As a by-product, we obtain a new proof for the expected number of connected components (clumps) in a line section of a circular Boolean model in ${R}^n$.},
  author       = {Edelsbrunner, Herbert and Nikitenko, Anton},
  issn         = {1095-7219},
  journal      = {Theory of Probability and its Applications},
  number       = {4},
  pages        = {595--614},
  publisher    = {SIAM},
  title        = {{Weighted Poisson–Delaunay mosaics}},
  doi          = {10.1137/S0040585X97T989726},
  volume       = {64},
  year         = {2020},
}

@misc{9878,
  author       = {Gupta, Chitrak and Khaniya, Umesh and Chan, Chun Kit and Dehez, Francois and Shekhar, Mrinal and Gunner, M.R. and Sazanov, Leonid A and Chipot, Christophe and Singharoy, Abhishek},
  publisher    = {American Chemical Society},
  title        = {{Movies}},
  doi          = {10.1021/jacs.9b13450.s002},
  year         = {2020},
}

@misc{9885,
  abstract     = {Data obtained from the fine-grained simulations used in Figures 2-5, data obtained from the coarse-grained numerical calculations used in Figure 6, and a sample script for the fine-grained simulation as a Jupyter notebook (ZIP)},
  author       = {Ucar, Mehmet C and Lipowsky, Reinhard},
  publisher    = {American Chemical Society },
  title        = {{MURL_Dataz}},
  doi          = {10.1021/acs.nanolett.9b04445.s002},
  year         = {2020},
}

@article{7473,
  abstract     = {How structural and functional properties of synapses relate to each other is a fundamental question in neuroscience. Electrophysiology has elucidated mechanisms of synaptic transmission, and electron microscopy (EM) has provided insight into morphological properties of synapses. Here we describe an enhanced method for functional EM (“flash and freeze”), combining optogenetic stimulation with high-pressure freezing. We demonstrate that the improved method can be applied to intact networks in acute brain slices and organotypic slice cultures from mice. As a proof of concept, we probed vesicle pool changes during synaptic transmission at the hippocampal mossy fiber-CA3 pyramidal neuron synapse. Our findings show overlap of the docked vesicle pool and the functionally defined readily releasable pool and provide evidence of fast endocytosis at this synapse. Functional EM with acute slices and slice cultures has the potential to reveal the structural and functional mechanisms of transmission in intact, genetically perturbed, and disease-affected synapses.},
  author       = {Borges Merjane, Carolina and Kim, Olena and Jonas, Peter M},
  issn         = {0896-6273},
  journal      = {Neuron},
  pages        = {992--1006},
  publisher    = {Elsevier},
  title        = {{Functional electron microscopy (“Flash and Freeze”) of identified cortical synapses in acute brain slices}},
  doi          = {10.1016/j.neuron.2019.12.022},
  volume       = {105},
  year         = {2020},
}

@article{8586,
  abstract     = {Cryo-electron microscopy (cryo-EM) of cellular specimens provides insights into biological processes and structures within a native context. However, a major challenge still lies in the efficient and reproducible preparation of adherent cells for subsequent cryo-EM analysis. This is due to the sensitivity of many cellular specimens to the varying seeding and culturing conditions required for EM experiments, the often limited amount of cellular material and also the fragility of EM grids and their substrate. Here, we present low-cost and reusable 3D printed grid holders, designed to improve specimen preparation when culturing challenging cellular samples directly on grids. The described grid holders increase cell culture reproducibility and throughput, and reduce the resources required for cell culturing. We show that grid holders can be integrated into various cryo-EM workflows, including micro-patterning approaches to control cell seeding on grids, and for generating samples for cryo-focused ion beam milling and cryo-electron tomography experiments. Their adaptable design allows for the generation of specialized grid holders customized to a large variety of applications.},
  author       = {Fäßler, Florian and Zens, Bettina and Hauschild, Robert and Schur, Florian KM},
  issn         = {1047-8477},
  journal      = {Journal of Structural Biology},
  keywords     = {electron microscopy, cryo-EM, EM sample preparation, 3D printing, cell culture},
  number       = {3},
  publisher    = {Elsevier},
  title        = {{3D printed cell culture grid holders for improved cellular specimen preparation in cryo-electron microscopy}},
  doi          = {10.1016/j.jsb.2020.107633},
  volume       = {212},
  year         = {2020},
}

@article{7387,
  abstract     = {Most bacteria accomplish cell division with the help of a dynamic protein complex called the divisome, which spans the cell envelope in the plane of division. Assembly and activation of this machinery are coordinated by the tubulin-related GTPase FtsZ, which was found to form treadmilling filaments on supported bilayers in vitro1, as well as in live cells, in which filaments circle around the cell division site2,3. Treadmilling of FtsZ is thought to actively move proteins around the division septum, thereby distributing peptidoglycan synthesis and coordinating the inward growth of the septum to form the new poles of the daughter cells4. However, the molecular mechanisms underlying this function are largely unknown. Here, to study how FtsZ polymerization dynamics are coupled to downstream proteins, we reconstituted part of the bacterial cell division machinery using its purified components FtsZ, FtsA and truncated transmembrane proteins essential for cell division. We found that the membrane-bound cytosolic peptides of FtsN and FtsQ co-migrated with treadmilling FtsZ–FtsA filaments, but despite their directed collective behaviour, individual peptides showed random motion and transient confinement. Our work suggests that divisome proteins follow treadmilling FtsZ filaments by a diffusion-and-capture mechanism, which can give rise to a moving zone of signalling activity at the division site.},
  author       = {Baranova, Natalia S. and Radler, Philipp and Hernández-Rocamora, Víctor M. and Alfonso, Carlos and Lopez Pelegrin, Maria D and Rivas, Germán and Vollmer, Waldemar and Loose, Martin},
  issn         = {2058-5276},
  journal      = {Nature Microbiology},
  pages        = {407--417},
  publisher    = {Springer Nature},
  title        = {{Diffusion and capture permits dynamic coupling between treadmilling FtsZ filaments and cell division proteins}},
  doi          = {10.1038/s41564-019-0657-5},
  volume       = {5},
  year         = {2020},
}

@article{7888,
  abstract     = {Embryonic stem cell cultures are thought to self-organize into embryoid bodies, able to undergo symmetry-breaking, germ layer specification and even morphogenesis. Yet, it is unclear how to reconcile this remarkable self-organization capacity with classical experiments demonstrating key roles for extrinsic biases by maternal factors and/or extraembryonic tissues in embryogenesis. Here, we show that zebrafish embryonic tissue explants, prepared prior to germ layer induction and lacking extraembryonic tissues, can specify all germ layers and form a seemingly complete mesendoderm anlage. Importantly, explant organization requires polarized inheritance of maternal factors from dorsal-marginal regions of the blastoderm. Moreover, induction of endoderm and head-mesoderm, which require peak Nodal-signaling levels, is highly variable in explants, reminiscent of embryos with reduced Nodal signals from the extraembryonic tissues. Together, these data suggest that zebrafish explants do not undergo bona fide self-organization, but rather display features of genetically encoded self-assembly, where intrinsic genetic programs control the emergence of order.},
  author       = {Schauer, Alexandra and Nunes Pinheiro, Diana C and Hauschild, Robert and Heisenberg, Carl-Philipp J},
  issn         = {2050-084X},
  journal      = {eLife},
  publisher    = {eLife Sciences Publications},
  title        = {{Zebrafish embryonic explants undergo genetically encoded self-assembly}},
  doi          = {10.7554/elife.55190},
  volume       = {9},
  year         = {2020},
}

@inproceedings{9633,
  abstract     = {The search for biologically faithful synaptic plasticity rules has resulted in a large body of models. They are usually inspired by – and fitted to – experimental data, but they rarely produce neural dynamics that serve complex functions. These failures suggest that current plasticity models are still under-constrained by existing data. Here, we present an alternative approach that uses meta-learning to discover plausible synaptic plasticity rules. Instead of experimental data, the rules are constrained by the functions they implement and the structure they are meant to produce. Briefly, we parameterize synaptic plasticity rules by a Volterra expansion and then use supervised learning methods (gradient descent or evolutionary strategies) to minimize a problem-dependent loss function that quantifies how effectively a candidate plasticity rule transforms an initially random network into one with the desired function. We first validate our approach by re-discovering previously described plasticity rules, starting at the single-neuron level and “Oja’s rule”, a simple Hebbian plasticity rule that captures the direction of most variability of inputs to a neuron (i.e., the first principal component). We expand the problem to the network level and ask the framework to find Oja’s rule together with an anti-Hebbian rule such that an initially random two-layer firing-rate network will recover several principal components of the input space after learning. Next, we move to networks of integrate-and-fire neurons with plastic inhibitory afferents. We train for rules that achieve a target firing rate by countering tuned excitation. Our algorithm discovers a specific subset of the manifold of rules that can solve this task. Our work is a proof of principle of an automated and unbiased approach to unveil synaptic plasticity rules that obey biological constraints and can solve complex functions.},
  author       = {Confavreux, Basile J and Zenke, Friedemann and Agnes, Everton J. and Lillicrap, Timothy and Vogels, Tim P},
  booktitle    = {Advances in Neural Information Processing Systems},
  issn         = {1049-5258},
  location     = {Vancouver, Canada},
  pages        = {16398--16408},
  title        = {{A meta-learning approach to (re)discover plasticity rules that carve a desired function into a neural network}},
  volume       = {33},
  year         = {2020},
}

@article{7885,
  abstract     = {Eukaryotic cells migrate by coupling the intracellular force of the actin cytoskeleton to the environment. While force coupling is usually mediated by transmembrane adhesion receptors, especially those of the integrin family, amoeboid cells such as leukocytes can migrate extremely fast despite very low adhesive forces1. Here we show that leukocytes cannot only migrate under low adhesion but can also transmit forces in the complete absence of transmembrane force coupling. When confined within three-dimensional environments, they use the topographical features of the substrate to propel themselves. Here the retrograde flow of the actin cytoskeleton follows the texture of the substrate, creating retrograde shear forces that are sufficient to drive the cell body forwards. Notably, adhesion-dependent and adhesion-independent migration are not mutually exclusive, but rather are variants of the same principle of coupling retrograde actin flow to the environment and thus can potentially operate interchangeably and simultaneously. As adhesion-free migration is independent of the chemical composition of the environment, it renders cells completely autonomous in their locomotive behaviour.},
  author       = {Reversat, Anne and Gärtner, Florian R and Merrin, Jack and Stopp, Julian A and Tasciyan, Saren and Aguilera Servin, Juan L and De Vries, Ingrid and Hauschild, Robert and Hons, Miroslav and Piel, Matthieu and Callan-Jones, Andrew and Voituriez, Raphael and Sixt, Michael K},
  issn         = {1476-4687},
  journal      = {Nature},
  pages        = {582–585},
  publisher    = {Springer Nature},
  title        = {{Cellular locomotion using environmental topography}},
  doi          = {10.1038/s41586-020-2283-z},
  volume       = {582},
  year         = {2020},
}

@article{8707,
  abstract     = {Dynamic changes in the three-dimensional (3D) organization of chromatin are associated with central biological processes, such as transcription, replication and development. Therefore, the comprehensive identification and quantification of these changes is fundamental to understanding of evolutionary and regulatory mechanisms. Here, we present Comparison of Hi-C Experiments using Structural Similarity (CHESS), an algorithm for the comparison of chromatin contact maps and automatic differential feature extraction. We demonstrate the robustness of CHESS to experimental variability and showcase its biological applications on (1) interspecies comparisons of syntenic regions in human and mouse models; (2) intraspecies identification of conformational changes in Zelda-depleted Drosophila embryos; (3) patient-specific aberrant chromatin conformation in a diffuse large B-cell lymphoma sample; and (4) the systematic identification of chromatin contact differences in high-resolution Capture-C data. In summary, CHESS is a computationally efficient method for the comparison and classification of changes in chromatin contact data.},
  author       = { Galan, Silvia and Machnik, Nick N and Kruse, Kai and Díaz, Noelia and Marti-Renom, Marc A and Vaquerizas, Juan M},
  issn         = {1546-1718},
  journal      = {Nature Genetics},
  pages        = {1247--1255},
  publisher    = {Springer Nature},
  title        = {{CHESS enables quantitative comparison of chromatin contact data and automatic feature extraction}},
  doi          = {10.1038/s41588-020-00712-y},
  volume       = {52},
  year         = {2020},
}

@article{8529,
  abstract     = {Practical quantum networks require low-loss and noise-resilient optical interconnects as well as non-Gaussian resources for entanglement distillation and distributed quantum computation. The latter could be provided by superconducting circuits but existing solutions to interface the microwave and optical domains lack either scalability or efficiency, and in most cases the conversion noise is not known. In this work we utilize the unique opportunities of silicon photonics, cavity optomechanics and superconducting circuits to demonstrate a fully integrated, coherent transducer interfacing the microwave X and the telecom S bands with a total (internal) bidirectional transduction efficiency of 1.2% (135%) at millikelvin temperatures. The coupling relies solely on the radiation pressure interaction mediated by the femtometer-scale motion of two silicon nanobeams reaching a <jats:italic>V</jats:italic><jats:sub><jats:italic>π</jats:italic></jats:sub> as low as 16 μV for sub-nanowatt pump powers. Without the associated optomechanical gain, we achieve a total (internal) pure conversion efficiency of up to 0.019% (1.6%), relevant for future noise-free operation on this qubit-compatible platform.},
  author       = {Arnold, Georg M and Wulf, Matthias and Barzanjeh, Shabir and Redchenko, Elena and Rueda Sanchez, Alfredo R and Hease, William J and Hassani, Farid and Fink, Johannes M},
  issn         = {2041-1723},
  journal      = {Nature Communications},
  keywords     = {General Biochemistry, Genetics and Molecular Biology, General Physics and Astronomy, General Chemistry},
  publisher    = {Springer Nature},
  title        = {{Converting microwave and telecom photons with a silicon photonic nanomechanical interface}},
  doi          = {10.1038/s41467-020-18269-z},
  volume       = {11},
  year         = {2020},
}

@article{9114,
  abstract     = {Microwave photonics lends the advantages of fiber optics to electronic sensing and communication systems. In contrast to nonlinear optics, electro-optic devices so far require classical modulation fields whose variance is dominated by electronic or thermal noise rather than quantum fluctuations. Here we demonstrate bidirectional single-sideband conversion of X band microwave to C band telecom light with a microwave mode occupancy as low as 0.025 ± 0.005 and an added output noise of less than or equal to 0.074 photons. This is facilitated by radiative cooling and a triply resonant ultra-low-loss transducer operating at millikelvin temperatures. The high bandwidth of 10.7 MHz and total (internal) photon conversion
efficiency of 0.03% (0.67%) combined with the extremely slow heating rate of 1.1 added output noise photons per second for the highest available pump power of 1.48 mW puts near-unity efficiency pulsed quantum transduction within reach. Together with the non-Gaussian resources of superconducting qubits this might provide the practical foundation to extend the range and scope of current quantum networks in analogy to electrical repeaters in classical fiber optic communication.},
  author       = {Hease, William J and Rueda Sanchez, Alfredo R and Sahu, Rishabh and Wulf, Matthias and Arnold, Georg M and Schwefel, Harald G.L. and Fink, Johannes M},
  issn         = {2691-3399},
  journal      = {PRX Quantum},
  number       = {2},
  publisher    = {American Physical Society},
  title        = {{Bidirectional electro-optic wavelength conversion in the quantum ground state}},
  doi          = {10.1103/prxquantum.1.020315},
  volume       = {1},
  year         = {2020},
}