@inproceedings{15012,
abstract = {We solve a problem of Dujmović and Wood (2007) by showing that a complete convex geometric graph on n vertices cannot be decomposed into fewer than n-1 star-forests, each consisting of noncrossing edges. This bound is clearly tight. We also discuss similar questions for abstract graphs.},
author = {Pach, János and Saghafian, Morteza and Schnider, Patrick},
booktitle = {31st International Symposium on Graph Drawing and Network Visualization},
isbn = {9783031492716},
issn = {1611-3349},
location = {Isola delle Femmine, Palermo, Italy},
pages = {339--346},
publisher = {Springer Nature},
title = {{Decomposition of geometric graphs into star-forests}},
doi = {10.1007/978-3-031-49272-3_23},
volume = {14465},
year = {2024},
}
@article{12738,
abstract = {We study turn-based stochastic zero-sum games with lexicographic preferences over objectives. Stochastic games are standard models in control, verification, and synthesis of stochastic reactive systems that exhibit both randomness as well as controllable and adversarial non-determinism. Lexicographic order allows one to consider multiple objectives with a strict preference order. To the best of our knowledge, stochastic games with lexicographic objectives have not been studied before. For a mixture of reachability and safety objectives, we show that deterministic lexicographically optimal strategies exist and memory is only required to remember the already satisfied and violated objectives. For a constant number of objectives, we show that the relevant decision problem is in NP∩coNP, matching the current known bound for single objectives; and in general the decision problem is PSPACE-hard and can be solved in NEXPTIME∩coNEXPTIME. We present an algorithm that computes the lexicographically optimal strategies via a reduction to the computation of optimal strategies in a sequence of single-objectives games. For omega-regular objectives, we restrict our analysis to one-player games, also known as Markov decision processes. We show that lexicographically optimal strategies exist and need either randomization or finite memory. We present an algorithm that solves the relevant decision problem in polynomial time. We have implemented our algorithms and report experimental results on various case studies.},
author = {Chatterjee, Krishnendu and Katoen, Joost P and Mohr, Stefanie and Weininger, Maximilian and Winkler, Tobias},
issn = {1572-8102},
journal = {Formal Methods in System Design},
pages = {40--80},
publisher = {Springer Nature},
title = {{Stochastic games with lexicographic objectives}},
doi = {10.1007/s10703-023-00411-4},
volume = {63},
year = {2024},
}
@article{14793,
abstract = {Superconductor/semiconductor hybrid devices have attracted increasing interest in the past years. Superconducting electronics aims to complement semiconductor technology, while hybrid architectures are at the forefront of new ideas such as topological superconductivity and protected qubits. In this work, we engineer the induced superconductivity in two-dimensional germanium hole gas by varying the distance between the quantum well and the aluminum. We demonstrate a hard superconducting gap and realize an electrically and flux tunable superconducting diode using a superconducting quantum interference device (SQUID). This allows to tune the current phase relation (CPR), to a regime where single Cooper pair tunneling is suppressed, creating a sin(2y) CPR. Shapiro experiments complement this interpretation and the microwave drive allows to create a diode with ≈ 100% efficiency. The reported results open up the path towards integration of spin qubit devices, microwave resonators and (protected) superconducting qubits on the same silicon technology compatible platform.},
author = {Valentini, Marco and Sagi, Oliver and Baghumyan, Levon and de Gijsel, Thijs and Jung, Jason and Calcaterra, Stefano and Ballabio, Andrea and Aguilera Servin, Juan L and Aggarwal, Kushagra and Janik, Marian and Adletzberger, Thomas and Seoane Souto, Rubén and Leijnse, Martin and Danon, Jeroen and Schrade, Constantin and Bakkers, Erik and Chrastina, Daniel and Isella, Giovanni and Katsaros, Georgios},
issn = {2041-1723},
journal = {Nature Communications},
publisher = {Springer Nature},
title = {{Parity-conserving Cooper-pair transport and ideal superconducting diode in planar germanium}},
doi = {10.1038/s41467-023-44114-0},
volume = {15},
year = {2024},
}
@article{18603,
abstract = {It is widely believed that information storage in neuronal circuits involves nanoscopic structural changes at synapses, resulting in the formation of synaptic engrams. However, direct evidence for this hypothesis is lacking. To test this conjecture, we combined chemical potentiation, functional analysis by paired pre-postsynaptic recordings, and structural analysis by electron microscopy (EM) and freeze-fracture replica labeling (FRL) at the rodent hippocampal mossy fiber synapse, a key synapse in the trisynaptic circuit of the hippocampus. Biophysical analysis of synaptic transmission revealed that forskolin-induced chemical potentiation increased the readily releasable vesicle pool size and vesicular release probability by 146% and 49%, respectively. Structural analysis of mossy fiber synapses by EM and FRL demonstrated an increase in the number of vesicles close to the plasma membrane and the number of clusters of the priming protein Munc13-1, indicating an increase in the number of both docked and primed vesicles. Furthermore, FRL analysis revealed a significant reduction of the distance between Munc13-1 and CaV2.1 Ca2+ channels, suggesting reconfiguration of the channel-vesicle coupling nanotopography. Our results indicate that presynaptic plasticity is associated with structural reorganization of active zones. We propose that changes in potential nanoscopic organization at synaptic vesicle release sites may be correlates of learning and memory at a plastic central synapse.},
author = {Kim, Olena and Okamoto, Yuji and Kaufmann, Walter and Brose, Nils and Shigemoto, Ryuichi and Jonas, Peter M},
issn = {1545-7885},
journal = {PLoS Biology},
number = {11},
publisher = {Public Library of Science},
title = {{Presynaptic cAMP-PKA-mediated potentiation induces reconfiguration of synaptic vesicle pools and channel-vesicle coupling at hippocampal mossy fiber boutons}},
doi = {10.1371/journal.pbio.3002879},
volume = {22},
year = {2024},
}
@misc{18296,
abstract = {It is widely believed that information storage in neuronal circuits involves nanoscopic structural changes at synapses, resulting in the formation of synaptic engrams. However, direct evidence for this hypothesis is lacking. To test this conjecture, we combined chemical potentiation, functional analysis by paired pre-postsynaptic recordings, and structural analysis by electron microscopy (EM) and freeze-fracture replica labeling (FRL) at the murine hippocampal mossy fiber synapse, a key synapse in the trisynaptic circuit of the hippocampus. Biophysical analysis of synaptic transmission revealed that forskolin-induced chemical potentiation increased the readily releasable vesicle pool size and vesicular release probability by 146% and 49%, respectively. Structural analysis of mossy fiber synapses by EM and FRL demonstrated an increase in the number of vesicles close to the plasma membrane and the number of clusters of the priming protein Munc13-1, indicating an increase in the number of both docked and primed vesicles. Furthermore, FRL analysis revealed a significant reduction of the distance between Munc13-1 and CaV2.1 Ca2+ channels, suggesting reconfiguration of the channel-vesicle coupling nanotopography. Our results indicate that presynaptic plasticity is associated with structural reorganization of active zones. We propose that changes in potential nanoscopic organization at synaptic vesicle release sites may be correlates of learning and memory at a plastic central synapse.},
author = {Kim, Olena},
keywords = {Hippocampal mossy fiber synapses, short-term potentiation, long-term potentiation, presynaptic plasticity, electron microscopy, freeze-fracture replica labeling, paired recordings, forskolin, cyclic adenosine monophosphate (cAMP), protein kinase A (PKA), neuromodulation, synaptic vesicle pools, presynaptic Ca2+ channels, Munc13, docking, priming, active zone},
publisher = {Institute of Science and Technology Austria},
title = {{Presynaptic cAMP-PKA-mediated potentiation induces reconfiguration of synaptic vesicle pools and channel-vesicle coupling at hippocampal mossy fiber boutons}},
doi = {10.15479/AT:ISTA:18296},
year = {2024},
}
@article{15401,
abstract = {Amide-proton-detected magic-angle-spinning NMR of deuterated proteins has become a main technique in NMR-based structural biology. In standard deuteration protocols that rely on D2O-based culture media, non-exchangeable amide sites remain deuterated, making these sites unobservable. Here we demonstrate that proteins produced with a H2O-based culture medium doped with deuterated cell lysate allow scientists to overcome this “reprotonation bottleneck” while retaining a high level of deuteration (ca. 80 %) and narrow linewidths. We quantified coherence lifetimes of several proteins prepared with this labeling pattern over a range of magic-angle-spinning (MAS) frequencies (40–100 kHz). We demonstrate that under commonly used conditions (50–60 kHz MAS), the amide 1H linewidths with our labeling approach are comparable to those of perdeuterated proteins and better than those of protonated samples at 100 kHz. For three proteins in the 33–50 kDa size range, many previously unobserved amides become visible. We report how to prepare the deuterated cell lysate for our approach from fractions of perdeuterated cultures which are usually discarded, and we show that such media can be used identically to commercial media. The residual protonation of Hα sites allows for well-resolved Hα-detected spectra and Hα resonance assignment, exemplified by the de novo assignment of 168 Hα sites in a 39 kDa protein. The approach based on this H2O/cell-lysate deuteration and MAS frequencies compatible with 1.3 or 1.9 mm rotors presents a strong sensitivity benefit over 0.7 mm 100 kHz MAS experiments.},
author = {Napoli, Federico and Guan, Jia-Ying and Arnaud, Charles-Adrien and Macek, Pavel and Fraga, Hugo and Breyton, Cécile and Schanda, Paul},
issn = {2699-0016},
journal = {Magnetic Resonance},
number = {1},
pages = {33--49},
publisher = {Copernicus Publications},
title = {{Deuteration of proteins boosted by cell lysates: High-resolution amide and Ha magic-angle-spinning (MAS) NMR without the reprotonation bottleneck}},
doi = {10.5194/mr-5-33-2024},
volume = {5},
year = {2024},
}
@article{15033,
abstract = {The GNOM (GN) Guanine nucleotide Exchange Factor for ARF small GTPases (ARF-GEF) is among the best studied trafficking regulators in plants, playing crucial and unique developmental roles in patterning and polarity. The current models place GN at the Golgi apparatus (GA), where it mediates secretion/recycling, and at the plasma membrane (PM) presumably contributing to clathrin-mediated endocytosis (CME). The mechanistic basis of the developmental function of GN, distinct from the other ARF-GEFs including its closest homologue GNOM-LIKE1 (GNL1), remains elusive. Insights from this study largely extend the current notions of GN function. We show that GN, but not GNL1, localizes to the cell periphery at long-lived structures distinct from clathrin-coated pits, while CME and secretion proceed normally in gn knockouts. The functional GN mutant variant GNfewerroots, absent from the GA, suggests that the cell periphery is the major site of GN action responsible for its developmental function. Following inhibition by Brefeldin A, GN, but not GNL1, relocates to the PM likely on exocytic vesicles, suggesting selective molecular associations en route to the cell periphery. A study of GN-GNL1 chimeric ARF-GEFs indicates that all GN domains contribute to the specific GN function in a partially redundant manner. Together, this study offers significant steps toward the elucidation of the mechanism underlying unique cellular and development functions of GNOM.},
author = {Adamowski, Maciek and Matijevic, Ivana and Friml, Jiří},
issn = {2050-084X},
journal = {eLife},
keywords = {General Immunology and Microbiology, General Biochemistry, Genetics and Molecular Biology, General Medicine, General Neuroscience},
publisher = {eLife Sciences Publications},
title = {{Developmental patterning function of GNOM ARF-GEF mediated from the cell periphery}},
doi = {10.7554/elife.68993},
volume = {13},
year = {2024},
}
@article{18491,
abstract = {Predicting the outcomes of adaptation is a major goal of evolutionary biology. When temporal changes in the environment mirror spatial gradients, it opens up the potential for predicting the course of adaptive evolution over time based on patterns of spatial genetic and phenotypic variation. We assessed this approach in a 30-year transplant experiment in the intertidal snail Littorina saxatilis. In 1992, snails were transplanted from a predation-dominated environment to one dominated by wave action. On the basis of spatial patterns, we predicted transitions in shell size and morphology, allele frequencies at positions throughout the genome, and chromosomal rearrangement frequencies. Observed changes closely agreed with predictions and transformation was both dramatic and rapid. Hence, adaptation can be predicted from knowledge of the phenotypic and genetic variation among populations.},
author = {Garcia Castillo, Diego Fernando and Barton, Nicholas H and Faria, Rui and Larsson, Jenny and Stankowski, Sean and Butlin, Roger and Johannesson, Kerstin and Westram, Anja M},
issn = {2375-2548},
journal = {Science Advances},
number = {41},
publisher = {AAAS},
title = {{Predicting rapid adaptation in time from adaptation in space: A 30-year field experiment in marine snails}},
doi = {10.1126/sciadv.adp2102},
volume = {10},
year = {2024},
}
@misc{18498,
abstract = {Scripts and data used in the research study Predicting rapid adaptation in time from adaptation in space: a 30-year field experiment in marine snails. https://doi.org/10.1101/2023.09.27.559715},
author = {Garcia Castillo, Diego Fernando and Barton, Nicholas H and Faria, Rui and Larsson, Jenny and Stankowski, Sean and Butlin, Roger and Johannesson, Kerstin and Westram, Anja M},
publisher = {Zenodo},
title = {{Data and code for: Predicting rapid adaptation in time from adaptation in space: a 30-year field experiment in marine snails}},
doi = {10.5281/ZENODO.12159343},
year = {2024},
}
@article{17202,
abstract = {Gate-tunable transmons (gatemons) employing semiconductor Josephson junctions have recently emerged as building blocks for hybrid quantum circuits. In this study, we present a gatemon fabricated in planar Germanium. We induce superconductivity in a two-dimensional hole gas by evaporating aluminum atop a thin spacer, which separates the superconductor from the Ge quantum well. The Josephson junction is then integrated into an Xmon circuit and capacitively coupled to a transmission line resonator. We showcase the qubit tunability in a broad frequency range with resonator and two-tone spectroscopy. Time-domain characterizations reveal energy relaxation and coherence times up to 75 ns. Our results, combined with the recent advances in the spin qubit field, pave the way towards novel hybrid and protected qubits in a group IV, CMOS-compatible material.},
author = {Sagi, Oliver and Crippa, Alessandro and Valentini, Marco and Janik, Marian and Baghumyan, Levon and Fabris, Giorgio and Kapoor, Lucky and Hassani, Farid and Fink, Johannes M and Calcaterra, Stefano and Chrastina, Daniel and Isella, Giovanni and Katsaros, Georgios},
issn = {2041-1723},
journal = {Nature Communications},
publisher = {Springer Nature},
title = {{A gate tunable transmon qubit in planar Ge}},
doi = {10.1038/s41467-024-50763-6},
volume = {15},
year = {2024},
}
@article{18087,
abstract = {We present a theory describing the interaction of structured light, such as light carrying orbital angular momentum, with molecules. The light-matter interaction Hamiltonian we derive is expressed through couplings between spherical gradients of the electric field and the (transition) electric multipole moments of a particle of any nontrivial rotation point group. Our model can therefore accommodate an arbitrary complexity of the molecular and electric field structure, and it can be straightforwardly extended to atoms or nanostructures. Applying this framework to rovibrational spectroscopy of molecules, we uncover the general mechanism of angular momentum exchange between the spin and orbital angular momenta of light, molecular rotation, and its center-of-mass motion. We show that the nonzero vorticity of Laguerre-Gaussian beams can strongly enhance certain rovibrational transitions that are considered forbidden in the case of nonhelical light. We discuss the experimental requirements for the observation of these forbidden transitions in state-of-the-art spatially resolved spectroscopy measurements.},
author = {Maslov, Mikhail and Koutentakis, Georgios and Hrast, Mateja and Heckl, Oliver H. and Lemeshko, Mikhail},
issn = {2643-1564},
journal = {Physical Review Research},
number = {3},
publisher = {American Physical Society},
title = {{Theory of angular momentum transfer from light to molecules}},
doi = {10.1103/physrevresearch.6.033277},
volume = {6},
year = {2024},
}
@phdthesis{18076,
abstract = {The new era of Ge has opened up new possibilities in quantum computing. The maturity of Ge
spin qubits is unquestioned, while hybrid semiconductor-superconductor Ge circuits are on track
to enter the game. Gate-tunable transmons (gatemons) employing semiconductor Josephson
junctions have recently emerged as building blocks for such hybrid quantum circuits. In this
thesis, we present a gatemon fabricated in planar Germanium. We induce superconductivity
in a two-dimensional hole gas by evaporating aluminum atop a thin spacer, which separates
the superconductor from the Ge quantum well. The Josephson junction is then integrated
into an Xmon circuit and capacitively coupled to a transmission line resonator. We showcase
the qubit tunability in a broad frequency range with resonator and two-tone spectroscopy.
Time-domain characterizations reveal energy relaxation and coherence times up to 75 ns. Our
results, combined with the recent advances in the spin qubit field, pave the way towards novel
hybrid and protected qubits in a group IV, CMOS-compatible material.},
author = {Sagi, Oliver},
issn = {2663-337X},
pages = {111},
publisher = {Institute of Science and Technology Austria},
title = {{Hybrid circuits on planar Germanium}},
doi = {10.15479/at:ista:18076},
year = {2024},
}
@misc{17196,
abstract = {This .zip File contains the data for the figures presented in the main text and supplementary material of "A gate tunable transmon qubit in planar Ge" by O.Sagi et al. The measurements were done using Qcodes. The description of the files and the instructions on opening the data can be found in the Readme. An additional Jupyter Notebook is attached that walks through the data analysis.},
author = {Sagi, Oliver},
publisher = {Institute of Science and Technology Austria},
title = {{A gate-tunable transmon in planar Ge}},
doi = {10.15479/AT:ISTA:17196},
year = {2024},
}
@misc{17362,
abstract = {This is the supplementary data for the paper titled "Single-nucleus atlas of the Artemia female reproductive system suggests germline repression of the Z chromosome", where we described the generation and analysis of single-nucleus expression and chromatin-accessibility data from the female reproductive system of Artemia franciscana. We compared our dataset to the published Drosophila single-nucleus data (over 400 million years of divergence) and highlighted the extreme conservation of several of the molecular pathways of oogenesis and meiosis. We found evidence of global transcriptional quiescence and chromatin condensation in late germ cells, highlighting the conserved role of this repressive stage in arthropod oogenesis. Additionally, we explored the expression patterns of the ZW sex chromosomes during oogenesis. Our data shows that the Z-chromosome is consistently downregulated in germline cells. While this is partly driven by a lack of dosage compensation in the germline, a subset of cells show stronger repression of the Z chromosome.},
author = {Elkrewi, Marwan N and Vicoso, Beatriz},
publisher = {Institute of Science and Technology Austria},
title = {{Data for: "Single-nucleus atlas of the Artemia female reproductive system suggests germline repression of the Z chromosome"}},
doi = {10.15479/AT:ISTA:17362},
year = {2024},
}
@article{21528,
abstract = {We present a framework for the end-to-end optimization of metasurface imaging systems that reconstruct targets using compressed sensing, a technique for solving underdetermined imaging problems when the target object exhibits sparsity (e.g., the object can be described by a small number of nonzero values, but the positions of these values are unknown). We nest an iterative, unapproximated compressed sensing reconstruction algorithm into our end-to-end optimization pipeline, resulting in an interpretable, data-efficient method for maximally leveraging metaoptics to exploit object sparsity. We apply our framework to super-resolution imaging and high-resolution depth imaging with a phase-change material. In both situations, our end-to-end framework effectively optimizes metasurface structures for compressed sensing recovery, automatically balancing a number of complicated design considerations to select an imaging measurement matrix from a complex, physically constrained manifold with millions of dimensions. The optimized metasurface imaging systems are robust to noise, significantly improving over random scattering surfaces and approaching the ideal compressed sensing performance of a Gaussian matrix, showing how a physical metasurface system can demonstrably approach the mathematical limits of compressed sensing.},
author = {Arya, Gaurav and Li, William F. and Roques-Carmes, Charles and Soljačić, Marin and Johnson, Steven G. and Lin, Zin},
issn = {2330-4022},
journal = {ACS Photonics},
keywords = {end-to-end, optimization, metasurface, imaging, compressed sensing},
number = {5},
pages = {2077--2087},
publisher = {American Chemical Society},
title = {{End-to-end optimization of metasurfaces for imaging with compressed sensing}},
doi = {10.1021/acsphotonics.4c00259},
volume = {11},
year = {2024},
}
@article{21582,
abstract = {Scintillation materials convert high-energy radiation to optical light through a complex multistage process. The last stage of the process is spontaneous light emission, which usually governs and limits the scintillator emission rate and light yield. For decades, scintillator research focused on developing faster-emitting materials or external photonic coatings for improving light yields. Here, we experimentally demonstrate a fundamentally different approach: enhancing the scintillation rate and yield via the Purcell effect, utilizing optical environment engineering to boost spontaneous emission. This enhancement is universally applicable to any scintillating material and dopant when the material’s nanoscale geometry is engineered. We design a thin multilayer nanophotonic scintillator, demonstrating Purcell-enhanced scintillation with 50% enhancement in emission rate and 80% enhancement in light yield. The emission is robust to fabrication disorder, further highlighting its potential for x-ray applications. Our results show prospects for bridging nanophotonics and scintillator science toward reduced radiation dosage and increased resolution for high-energy particle detection.},
author = {Kurman, Yaniv and Lahav, Neta and Schuetz, Roman and Shultzman, Avner and Roques-Carmes, Charles and Lifshits, Alon and Zaken, Segev and Lenkiewicz, Tom and Strassberg, Rotem and Be’er, Orr and Bekenstein, Yehonadav and Kaminer, Ido},
issn = {2375-2548},
journal = {Science Advances},
number = {44},
publisher = {American Association for the Advancement of Science},
title = {{Purcell-enhanced x-ray scintillation}},
doi = {10.1126/sciadv.adq6325},
volume = {10},
year = {2024},
}
@article{21672,
abstract = {We present a framework for the end-to-end optimization of metasurface imaging systems that reconstruct targets using compressed sensing, a technique for solving underdetermined imaging problems when the target object exhibits sparsity (i.e. the object can be described by a small number of non-zero values, but the positions of these values are unknown). We nest an iterative, unapproximated compressed sensing reconstruction algorithm into our end-to-end optimization pipeline, resulting in an interpretable, data-efficient method for maximally leveraging metaoptics to exploit object sparsity. We apply our framework to super-resolution imaging and high-resolution depth imaging with a phase-change material. In both situations, our end-to-end framework computationally discovers optimal metasurface structures for compressed sensing recovery, automatically balancing a number of complicated design considerations to select an imaging measurement matrix from a complex, physically constrained manifold with millions ofdimensions. The optimized metasurface imaging systems are robust to noise, significantly improving over random scattering surfaces and approaching the ideal compressed sensing performance of a Gaussian matrix, showing how a physical metasurface system can demonstrably approach the mathematical limits of compressed sensing.},
author = {Arya, Gaurav and Li, William F. and Roques-Carmes, Charles and Soljačić, Marin and Johnson, Steven G. and Lin, Zin},
issn = {2330-4022},
journal = {ACS Photonics},
keywords = {end-to-end, optimization, metasurface, imaging, compressed sensing},
publisher = {American Chemical Society},
title = {{End-to-end optimization of metasurfaces for imaging with compressed sensing}},
doi = {10.1021/acsphotonics.4c00259},
year = {2024},
}
@article{21529,
abstract = {A central challenge in the emerging field of free-electron quantum optics is to achieve strong quantum interaction and single-photon nonlinearity between a flying free electron and a photonic mode. Existing schemes are intrinsically limited by electron diffraction, which puts an upper bound on the interaction length and, therefore, on the strength of quantum coupling and nonlinearity. Here, we propose “free-electron fibers”: effectively one-dimensional photonic systems where free electrons copropagate with two guided modes. The first mode applies a ponderomotive trap to the free electron, removing the limitations due to electron diffraction. The second mode strongly couples to the guided free electron with an enhanced coupling that is orders of magnitude larger than previous designs. The extended interaction lengths enabled by our scheme allow for strong single-photon nonlinearities mediated by free electrons. We predict novel quantum effects in our system such as deterministic single-photon emission and nonlinear multimode dynamics. Our proposal paves the way toward the realization of heralded macroscopic nonclassical light generation, deterministic single-photon sources, and quantum gates controlled by free-electron–photon interactions.},
author = {Karnieli, Aviv and Roques-Carmes, Charles and Rivera, Nicholas and Fan, Shanhui},
issn = {2330-4022},
journal = {ACS Photonics},
keywords = {quantum optics, free electrons, single photon nonlinearity, electron-photon interaction},
number = {8},
pages = {3401--3411},
publisher = {American Chemical Society},
title = {{Strong coupling and single-photon nonlinearity in free-electron quantum optics}},
doi = {10.1021/acsphotonics.4c00908},
volume = {11},
year = {2024},
}
@article{21540,
abstract = {Probabilistic machine learning utilizes controllable sources of randomness to encode uncertainty and enable statistical modeling. Harnessing the pure randomness of quantum vacuum noise, which stems from fluctuating electromagnetic fields, has shown promise for high speed and energy-efficient stochastic photonic elements. Nevertheless, photonic computing hardware which can control these stochastic elements to program probabilistic machine learning algorithms has been limited. Here, we implement a photonic probabilistic computer consisting of a controllable stochastic photonic element – a photonic probabilistic neuron (PPN). Our PPN is implemented in a bistable optical parametric oscillator (OPO) with vacuum-level injected bias fields. We then program a measurement-and-feedback loop for time-multiplexed PPNs with electronic processors (FPGA or GPU) to solve certain probabilistic machine learning tasks. We showcase probabilistic inference and image generation of MNIST-handwritten digits, which are representative examples of discriminative and generative models. In both implementations, quantum vacuum noise is used as a random seed to encode classification uncertainty or probabilistic generation of samples. In addition, we propose a path towards an all-optical probabilistic computing platform, with an estimated sampling rate of ~1 Gbps and energy consumption of ~5 fJ/MAC. Our work paves the way for scalable, ultrafast, and energy-efficient probabilistic machine learning hardware.},
author = {Choi, Seou and Salamin, Yannick and Roques-Carmes, Charles and Dangovski, Rumen and Luo, Di and Chen, Zhuo and Horodynski, Michael and Sloan, Jamison and Uddin, Shiekh Zia and Soljačić, Marin},
issn = {2041-1723},
journal = {Nature Communications},
publisher = {Springer Nature},
title = {{Photonic probabilistic machine learning using quantum vacuum noise}},
doi = {10.1038/s41467-024-51509-0},
volume = {15},
year = {2024},
}
@article{21564,
abstract = {Multimode quantum light is enticing for several applications, spanning imaging, spectroscopy, communication, and more. Parametric nonlinear processes have been vital in realizing squeezed and other quantum states of light. However, most work exploiting these processes has focused on generating multimode squeezed vacua and squeezing in mode superpositions (supermodes). Bright squeezing in multiple discrete frequency modes, if realized, could unlock novel applications in quantum-enhanced spectroscopy and optical quantum computing. Here, we show how dissipation engineering of a multimode nonlinear cavity with cascaded three-wave-mixing processes allows us to shape above-threshold frequency combs that feature strong single-mode output amplitude noise squeezing over 10 dB below the shot-noise limit, tunable across the comb. In addition, we demonstrate squeezing for multiple discrete frequency modes above threshold. This bright squeezing arises from enhancement of the (noiseless) nonlinear rate relative to decay rates in the system due to the cascaded generation of photons in a single idler “bath” mode. A natural consequence of the strong nonlinear coupling in our system is the creation of an effective cavity in the synthetic frequency dimension that sustains Bloch oscillations in the modal energy distribution. Bloch mode engineering could provide an opportunity to better control nonlinear energy flow in the synthetic frequency dimension, with exciting applications in quantum random walks and topological photonics. Lastly, we show evidence of long-range correlations in amplitude noise between discrete frequency modes, enabling long-range entanglement in a synthetic frequency dimension and providing a new resource for quantum communication.},
author = {Pontula, Sahil and Salamin, Yannick and Roques-Carmes, Charles and Soljačić, Marin},
issn = {2691-3399},
journal = {PRX Quantum},
number = {4},
publisher = {American Physical Society},
title = {{Shaping quantum noise through cascaded nonlinear processes in a dissipation-engineered multimode cavity}},
doi = {10.1103/prxquantum.5.040345},
volume = {5},
year = {2024},
}