Latest in quant-ph

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Colloquium: Atomic spin chains on surfacesApr 22 2019In the present Colloquium, we focus on the properties of 1-D magnetic systems on solid surfaces. From the emulation of 1-D quantum phases to the potential realization of Majorana edge states, spin chains are unique systems to study. The advent of scanning ... More
Evaluating the Maximal Violation of the Original Bell Inequality by Two-Qudit States Exhibiting Perfect Correlations/AnticorrelationsApr 22 2019We introduce the general class of symmetric two-qubit states guaranteeing the perfect correlation or anticorrelation of Alice and Bob outcomes whenever some spin observable is measured at both sites. We prove that, for all states from this class, the ... More
Coherence quantifiers from the viewpoint of their decreases in the measurement processApr 22 2019Measurements can be considered as a genuine example of processes that crush quantum coherence. In the case of an observable with degeneracy, the formulations of L\"{u}ders and von Neumann are known. These pictures postulate the two different states of ... More
Security bound of continuous-variable measurement-device-independent quantum key distribution with imperfect phase reference calibrationApr 22 2019Phase reference calibration is a necessary procedure in practical continuous-variable measurement-device-independent quantum key distribution (CV-MDI-QKD) for the need of Bell-State Measurement (BSM). However, the phase reference calibration may become ... More
Temporally Asymmetric Bi-photon States in Cavity Enhanced Optical Parametric ProcessesApr 22 2019Generation and control of quantum states of light on an integrated platform has become an essential tool for scalable quantum technologies. Chip scale sources such as nonlinear optical microcavities have been demonstrated to efficiently generate entangled ... More
Experimental realization of 105-qubit random access quantum memoryApr 21 2019Random access memory is an indispensable device for classical information technology. Analog to this, for quantum information technology, it is desirable to have a random access quantum memory with many memory cells and programmable access to each cell. ... More
Quantum state preparation for coupled period tripling oscillatorsApr 21 2019We investigate the quantum transition to a correlated state of coupled oscillators in the regime where they display period tripling in response to a drive at triple the eigenfrequency. Correlations are formed between the discrete oscillation phases of ... More
Generation and detection of spin-orbit coupled neutron beamsApr 21 2019Spin-orbit coupling of light has come to the fore in nano-optics and plasmonics, and is a key ingredient of topological photonics and chiral quantum optics. We demonstrate a basic tool for incorporating analogous effects into neutron optics: the generation ... More
Exact solutions of the sextic oscillator from the bi-confluent Heun equationApr 20 2019The sextic oscillator is discussed as a potential obtained from the bi-confluent Heun equation after a suitable variable transformation. Following earlier results, the solutions of this differential equation are expressed as a series expansion of Hermite ... More
Second order dispersion by optimised rotation pulsesApr 20 2019Optimal control has become a useful tool in designing pulses for complicated control problems, beyond the limit of classical hard pulses. Building on past research of broadband pulses performing effective unitary propagation (BURBOP), research presented ... More
Detecting subsystem symmetry-protected topological order via entanglement entropyApr 20 2019Subsystem symmetry-protected topological (SSPT) order is a type of quantum order that is protected by symmetries acting on lower-dimensional subsystems of the entire system. In this paper, we show how SSPT order can be characterized and detected by a ... More
$XY$-mixers: analytical and numerical results for QAOAApr 19 2019The Quantum Alternating Operator Ansatz (QAOA) is a promising gate-model meta-heuristic for combinatorial optimization. Applying the algorithm to problems with constraints presents an implementation challenge for near-term quantum resources. This work ... More
Spooky Work at a Distance: an Interaction-Free Quantum Measurement-Driven EngineApr 19 2019Recent progress in the science of quantum measurement has focused on the energy associated with the wavefunction collapse process. Energy may be stochastically transferred from the measurement probe to the system being measured, such that a highly efficient ... More
Microwave to optical conversion with atoms on a superconducting chipApr 19 2019We describe a scheme to coherently convert a microwave photon of a superconducting co-planar waveguide resonator to an optical photon emitted into a well-defined temporal and spatial mode. The conversion is realized by a cold atomic ensemble trapped above ... More
Experimental observation of dynamical bulk-surface correspondence for topological phasesApr 19 2019We experimentally demonstrate a dynamical classification approach for investigation of topological quantum phases using a solid-state spin system through nitrogen-vacancy (NV) center in diamond. Similar to the bulkboundary correspondence in real space ... More
Optimizing Quantum Programs against Decoherence: Delaying Qubits into Quantum SuperpositionApr 18 2019Quantum computing technology has reached a second renaissance in the last decade. However, in the NISQ era pointed out by John Preskill in 2018, quantum noise and decoherence, which affect the accuracy and execution effect of quantum programs, cannot ... More
Microwave-to-optical conversion via four-wave-mixing in a cold ytterbium ensembleApr 18 2019Interfacing superconducting qubits with optical photons requires noise-free microwave-to-optical transducers, a technology currently not realized at the single-photon level. We propose to use four-wave-mixing in an ensemble of cold ytterbium (Yb) atoms ... More
Quantum Assisted Clustering Algorithms for NISQ-Era DevicesApr 18 2019In this article, we demonstrate how to view stoquastic adiabatic quantum computing from a purely graph-theoretic perspective, and then use this structure to design hybrid quantum-classical clustering algorithms. These algorithms require a number of qubits ... More
Fast state and trap rotation of a particle in an anisotropic potentialApr 18 2019We study the dynamics of a quantum or classical particle in a two-dimensional rotating anisotropic harmonic potential. By a sequence of symplectic transformations for constant rotation velocity we find uncoupled normal generalized coordinates and conjugate ... More
Bounding the sets of classical and quantum correlations in networksApr 18 2019We present a method that allows the study of classical and quantum correlations in networks with causally-independent parties, such as the scenario underlying entanglement swapping. By imposing relaxations of factorization constraints in a form compatible ... More
Quantum Lower Bounds for Approximate Counting via Laurent PolynomialsApr 18 2019This paper proves new limitations on the power of quantum computers to solve approximate counting -- that is, multiplicatively estimating the size of a nonempty set $S\subseteq [N]$. Given only a membership oracle for $S$, it is well known that approximate ... More
A polar decomposition for quantum channels (with applications to bounding error propagation in quantum circuits)Apr 18 2019Inevitably, assessing the overall performance of a quantum computer must rely on characterizing some of its elementary constituents and, from this information, formulate a broader statement concerning more complex constructions thereof. However, given ... More
Ensemble-induced strong light-matter coupling of a single quantum emitterApr 18 2019We discuss a technique to strongly couple a single target quantum emitter to a cavity mode, which is enabled by virtual excitations of a nearby mesoscopic ensemble of emitters. A collective coupling of the latter to both the cavity and the target emitter ... More
Two localization lengths in the Anderson transition on random graphsApr 18 2019We present a full description of the nonergodic properties of wavefunctions on random graphs without boundary in the localized and critical regimes of the Anderson transition. We find that they are characterized by two localization lengths: the largest ... More
Quantum maximum power transfer theoremApr 18 2019We discover the quantum analog of the well-known classical maximum power transfer theorem. Our theoretical framework considers the continuous steady-state problem of coherent energy transfer through an N-node bosonic network coupled to an external dissipative ... More
Communication Cost for Non-Markovianity of Tripartite Quantum States: A Resource Theoretic ApproachApr 18 2019To quantify non-Markovianity of tripartite quantum states from an operational viewpoint, we introduce a class $\Omega^*$ of operations performed by three distant parties. A tripartite quantum state is a free state under $\Omega^*$ if and only if it is ... More
Integration of Single Photon Emitters in 2D Layered Materials with a Silicon Nitride Photonic ChipApr 18 2019Photonic integrated circuits (PICs) enable miniaturization of optical quantum circuits because several optic and electronic functionalities can be added on the same chip. Single photon emitters (SPEs) are central building blocks for such quantum circuits ... More
Perfect State Transfer on Weighted Graphs of the Johnson SchemeApr 18 2019We characterize perfect state transfer on real-weighted graphs of the Johnson scheme $\mathcal{J}(n,k)$. Given $\mathcal{J}(n,k)=\{A_1, A_2, \cdots, A_k\}$ and $A(X) = w_0A_0 + \cdots + w_m A_m$, we show, using classical number theory results, that $X$ ... More
A doubly exponential upper bound on noisy EPR states for binary gamesApr 18 2019This paper initiates the study of a class of entangled-games, mono-state games, denoted by $(G,\psi)$, where $G$ is a two-player one-round game and $\psi$ is a bipartite state independent of the game $G$. In the mono-state game $(G,\psi)$, the players ... More
A new density functional method for electronic structure calculation of atoms and moleculesApr 18 2019This chapter concerns with the recent development of a new DFT methodology for accurate, reliable prediction of many-electron systems. Background, need for such a scheme, major difficulties encountered, as well as their potential remedies are discussed ... More
Decoherence of dipolar spin ensembles in diamondApr 18 2019We present a combined theoretical and experimental study of solid-state spin decoherence in an electronic spin bath, focusing specifically on ensembles of nitrogen vacancy (NV) color centers in diamond and the associated substitutional nitrogen spin bath. ... More
Gentle Measurement of Quantum States and Differential PrivacyApr 18 2019In differential privacy (DP), we want to query a database about n users, in a way that "leaks at most eps about any individual user," even conditioned on any outcome of the query. Meanwhile, in gentle measurement, we want to measure n quantum states, ... More
Parity-Enhanced Quantum Optimal MeasurementsApr 18 2019We find a large class of pure and mixed input states with which the phase estimation precision saturates the Cramer-Rao bound under the compound measurements of parity and particle number. We further propose a quantum-phase-estimation protocol for arbitrary ... More
Almost thermal operations: inhomogeneous reservoirsApr 18 2019The resource theory of thermal operations explains the state transformations that are possible in a very specific thermodynamic setting: there is only one thermal bath, auxiliary systems can only be in corresponding thermal state (free states), and the ... More
Optimal gauge for the multimode Rabi model in circuit QEDApr 18 2019In circuit QED, a Rabi model can be derived by truncating the Hilbert space of the anharmonic qubit coupled to a linear, reactive environment. This truncation breaks the gauge invariance present in the full Hamiltonian. We analyze the determination of ... More
DFT calculations of atoms and molecules in Cartesian gridsApr 18 2019Density functional theory (DFT) has emerged as one of the most versatile and lucrative approaches in electronic structure calculations of many-electron systems in past four decades. Here we give an account of the development of a variational DFT method ... More
A general method for central potentials in quantum mechanicsApr 18 2019We focus on a recently developed generalized pseudospectral method for accurate, efficient treatment of certain central potentials of interest in various branches in quantum mechanics, usually having singularity. Essentially this allows optimal, nonuniform ... More
A density functional method for general excited states in atomsApr 18 2019This chapter presents the development of a density functional theory (DFT)-based method for accurate, reliable treatment of various resonances in atoms. Many of these are known to be notorious for their strong correlation, proximity to more than one thresholds, ... More
Equilibrium properties and decoherence of an open harmonic oscillatorApr 18 2019The equilibrium properties of an open harmonic oscillator are considered in three steps: First the creation and destruction operators are generalized for open dynamics and the creation operator is used to construct coherent states. The second step consists ... More
Contextuality without access to a tomographically complete setApr 18 2019The non-classicality of single quantum systems can be formalised using the notion of contextuality. But can contextuality be convincingly demonstrated in an experiment, without reference to the quantum formalism? The operational approach to contextuality ... More
Precise computation of rovibronic resonances of molecular hydrogen: $EF\ ^1Σ_\mathrm{g}^+$ inner-well rotational statesApr 18 2019Selected states of the $EF\ ^1\Sigma_\mathrm{g}^+$ electronic manifold of the hydrogen molecule are computed as resonances of the four-body problem. Systematic improvement of the basis representation for the variational treatment is achieved through an ... More
Quantum link bootstrapping using a RuleSet-based communication protocolApr 18 2019Establishing end-to-end quantum connections requires quantified link characteristics, and operations need to coordinate decision-making between nodes across a network. We introduce the RuleSet-based communication protocol for supporting quantum operations ... More
Radial basis function network using Lambert-Tsallis Wq functionApr 18 2019The present work brings two applications of the Lambert-Tsallis Wq function in radial basis function networks (RBFN). Initially, a RBFN is used to discriminate between entangled and disentangled bipartite of qubit states. The kernel used is based on the ... More
Subspace Variational Quantum SimulatorApr 18 2019Quantum simulation is one of the key applications of quantum computing, which can accelerate research and development in chemistry, material science, etc. Here, we propose an efficient method to simulate the time evolution driven by a static Hamiltonian, ... More
Vacuum Decay in Real Time and Imaginary Time FormalismsApr 18 2019We analyze vacuum tunneling in quantum field theory in a general formalism by using the Wigner representation. In the standard instanton formalism, one usually approximates the initial false vacuum state by an eigenstate of the field operator, imposes ... More
Two-electron-spin ratchets as a platform for microwave-free dynamic nuclear polarization of arbitrary material targetsApr 18 2019Optically-pumped color centers in semiconductor powders can potentially induce high levels of nuclear spin polarization in surrounding solids or fluids at or near ambient conditions, but complications stemming from the random orientation of the particles ... More
Spin image of an atomic vapor cell with a resolution smaller than the diffusion crosstalk free distanceApr 18 2019The diffusion crosstalk free distance is an important parameter for spin images in atomic vapor cells and is also regarded as a limit on the spatial resolution. However, by modulating the pumping light both spatially and temporally using a digital micromirror ... More
Necessary and Sufficient Conditions on Measurements of Quantum ChannelsApr 17 2019Quantum supermaps are a higher-order generalization of quantum maps, taking quantum maps to quantum maps. It is known that any completely positive, trace non-increasing (CPTNI) map can be performed as part of a quantum measurement. By providing an explicit ... More
Power narrowing: Counteracting Doppler broadening in two-color transitionsApr 17 2019Doppler broadening in thermal ensembles degrades the absorption cross-section and the coherence time of collective excitations. In two photon transitions, it is common to assume that this problem becomes worse with larger wavelength mismatch. Here we ... More
Shortcuts to adiabaticity: concepts, methods, and applicationsApr 17 2019Shortcuts to adiabaticity (STA) are fast routes to the final results of slow, adiabatic changes of the controlling parameters of a system. The shortcuts are designed by a set of analytical and numerical methods suitable for different systems and conditions. ... More
Integrating Neural Networks with a Quantum Simulator for State ReconstructionApr 17 2019We demonstrate quantum many-body state reconstruction from experimental data generated by a programmable quantum simulator, by means of a neural network model incorporating known experimental errors. Specifically, we extract restricted Boltzmann machine ... More
Distributed sampling, quantum communication witnesses, and measurement incompatibilityApr 17 2019We study prepare-and-measure experiments where the sender (Alice) receives trusted quantum inputs but has an untrusted state-preparation device and the receiver (Bob) has a fully-untrusted measurement device. A distributed-sampling task naturally arises ... More
The holographic dual of Rényi relative entropyApr 17 2019The relative entropy is a measure of the distinguishability of two quantum states. A great deal of progress has been made in the study of the relative entropy between an excited state and the vacuum state of a conformal field theory (CFT) reduced to a ... More
Round robin differential phase shift quantum key distribution with yes-no detectors onlyApr 17 2019In the original round-robin differential-phase-shift (RRDPS) quantum key distribution and its improved method, the photon-number-resolving detectors are must for the security. We present a RRDPS protocol with yes-no detectors only. We get the upper bounds ... More
Dynamical spin-orbit coupling of a quantum gasApr 17 2019We realize the dynamical 1D spin-orbit-coupling (SOC) of a Bose-Einstein condensate confined within an optical cavity. The SOC emerges through spin-correlated momentum impulses delivered to the atoms via Raman transitions. These are effected by classical ... More
Preservation of no-signalling principle in parity-time symmetric quantum systemsApr 17 2019We look into the possibility of entanglement generation in a parity(P)-time(T)-symmetric framework and demonstrate the non-violation of non-signalling principle for the case of bipartite systems when at least one is guided by PT-symmetric quantum mechanics. ... More
Precision spectroscopy of negative-ion resonances in Rydberg moleculesApr 17 2019The level structure of negative-ions near the electron detachment limit dictates the low-energy scattering of an electron with the parent neutral atom. We demonstrate that a single ultracold atom bound inside a Rydberg orbit forming an ultralong-range ... More
Slow and fast light behavior of single photons from a quantum dot interacting with the excited state hyperfine structure of the Cesium D1-lineApr 17 2019Hybrid interfaces between distinct quantum systems play a major role in the implementation of quantum networks. Quantum states have to be stored in memories to synchronize the photon arrival times for entanglement swapping by projective measurements in ... More
Quantum advantage by relational queries about physically realizable equivalence classesApr 17 2019Relational quantum queries are sometimes capable to effectively decide between collections of mutually exclusive elementary cases without completely resolving and determining those individual instances. Thereby the set of mutually exclusive elementary ... More
Entanglement production by statistical operatorsApr 17 2019In the problem of entanglement there exist two different notions. One is the entanglement of a quantum state, characterizing the state structure. The other is entanglement production by quantum operators, describing the action of operators in the given ... More
A class of genuinely high-dimensionally entangled states with a positive partial transposeApr 17 2019Entangled states with a positive partial transpose (so-called PPT states) are central to many interesting problems in quantum theory. On one hand, they are considered to be weakly entangled, since no pure state entanglement can be distilled from them. ... More
Controlling Dipolar Exchange Interactions in a Dense 3D Array of Large Spin FermionsApr 17 2019Dipolar interactions are ubiquitous in nature and rule the behavior of a broad range of systems spanning from energy transfer in biological systems to quantum magnetism. Here, we study magnetization-conserving dipolar induced spin-exchange dynamics in ... More
Entanglement and objectivity in pure dephasing modelsApr 17 2019We study the relation between the emergence of objectivity and qubit-environment entanglement generation. We find that although entanglement with the unobserved environments is irrelevant (since sufficiently strong decoherence can occur regardless), entanglement ... More
A silicon quantum-dot-coupled nuclear spin qubitApr 17 2019Nuclear spins in the solid state have long been envisaged as a platform for quantum computing, due to their long coherence times and excellent controllability. Measurements can be performed via localised electrons, for example those in single atom dopants ... More
On the modular operator of mutli-component regions in chiral CFTApr 17 2019We introduce an approach to find the Tomita-Takesaki modular flow for multi-component regions in chiral conformal field theory. Our method is based only locality (or braid-relations) of primary fields and the so-called Kubo-Martin-Schwinger (KMS) condition. ... More
Generation of optical Fock and W states with single-atom-based bright quantum scissorsApr 17 2019We introduce a multi-step protocol for optical quantum state engineering that performs as deterministic "bright quantum scissors" (BQS), namely truncates an arbitrary input quantum state to have at least a certain number of photons. The protocol exploits ... More
Observation of PT-symmetric quantum interferenceApr 17 2019Parity-Time (PT) symmetric quantum mechanics is a complex extension of conventional Hermitian quantum mechanics in which physical observables possess a real eigenvalue spectrum. However, an experimental demonstration of the true quantum nature of PT symmetry ... More
Lorentz-invariant, retrocausal, and deterministic hidden variablesApr 17 2019We review several no-go theorems attributed to Gisin and Hardy, Conway and Kochen purporting the impossibility of Lorentz-invariant deterministic hidden-variable model for explaining quantum nonlocality. Those theorems claim that the only known solution ... More
Collectively induced exceptional points of quantum emitters coupled to nanoparticle surface plasmonsApr 17 2019Exceptional points, resulting from non-Hermitian degeneracies, have the potential to enhance the capabilities of quantum sensing. Thus, finding exceptional points in different quantum systems is vital for developing such future sensing devices. Taking ... More
Highly-polarizable ion in a Paul trapApr 17 2019Usually the influence of the quadratic Stark effect on an ion's trapping potential is minuscule and only needs to be considered in atomic clock experiments. In this work we excite a trapped ion to a Rydberg state with polarizability $\sim$~eight orders ... More
Topological pumping of edge states via adiabatic passageApr 17 2019Topological pumping of edge states in finite crystals or quasicrystals with non-trivial topological phases provides a powerful means for robust excitation transfer. In most schemes of topological pumping, the edge states become delocalized and immersed ... More
Deep Learning-Assisted Classification of Site-Resolved Quantum Gas Microscope ImagesApr 17 2019We present a novel method for the analysis of quantum gas microscope images, which uses deep learning to improve the fidelity with which lattice sites can be classified as occupied or unoccupied. Our method is especially suited to addressing the case ... More
Practical security of continuous-variable quantum key distribution with reduced optical attenuationApr 17 2019In a practical CVQKD system, the optical attenuator can adjust the Gaussian-modulated coherent states and the local oscillator signal to an optimal value for guaranteeing the security of the system and optimizing the performance of the system. However, ... More
Nanophotonic quantum storage at telecommunications wavelengthApr 17 2019Quantum memories for light are important components for future long distance quantum networks. We present on-chip quantum storage of telecommunications band light at the single photon level in an ensemble of erbium-167 ions in an yttrium orthosilicate ... More
Quantum Circuits for maximally entangled statesApr 16 2019We design a series of quantum circuits that generate absolute maximally entangled (AME) states to benchmark a quantum computer. A relation between graph states and AME states can be exploited to optimize the structure of the circuits and minimize their ... More
Triplet harvesting in the polaritonic regime: a variational polaron approachApr 16 2019We explore the electroluminescence efficiency for a quantum mechanical model of a large number of molecular emitters embedded in an optical microcavity. We characterize the circumstances under which a microcavity enhances harvesting of triplet excitons ... More
Entanglement preserving local thermalizationApr 16 2019We investigate whether entanglement can survive the thermalization of subsystems. We present two equivalent formulations of this problem: 1. Can two isolated agents, accessing only pre-shared randomness, locally thermalize arbitrary input states while ... More
Thermodynamically optimal creation of correlationsApr 16 2019Correlations lie at the heart of almost all scientific predictions. It is therefore of interest to ask whether there exist general limitations to the amount of correlations that can be created at a finite amount of invested energy. Within quantum thermodynamics ... More
Vector Vortex Beam Emitter Embedded in a Photonic ChipApr 16 2019Vector vortex beam simultaneously carrying spin and orbital angular momentum of light promises additional degrees of freedom for modern optics and emerging resources for both classical and quantum information technologies. The inherently infinite dimensions ... More
On superstatistics of energy for a free quantum Brownian particleApr 16 2019We consider energetics of a free quantum Brownian particle coupled to thermostat of temperature $T$ and study this problem in terms of the lately formulated quantum analogue of the energy equipartition theorem. We show how this quantum counterpart can ... More
Activation of nonlocality in bound entanglementApr 16 2019We discuss the relation between entanglement and nonlocality in the hidden nonlocality scenario. Hidden nonlocality signifies nonlocality that can be activated by applying local filters to a particular state that admits a local hidden-variable model in ... More
Simultaneous structures in convex signal recovery - revisiting the convex combination of normsApr 16 2019In compressed sensing one uses known structures of otherwise unknown signals to recover them from as few linear observations as possible. The structure comes in form of some compressibility including different notions of sparsity and low rankness. In ... More
The Collapse Before a Quantum Jump TransitionApr 16 2019We may infer a transition $|n \rangle \to |m \rangle$ between energy eigenstates of an open quantum system by observing the emission of a photon of Bohr frequency $\omega_{mn} = (E_n-E_m) / \hbar$. In addition to the "collapses" to the state $|m\rangle$, ... More
Nonlinear Dynamics of the Cold Atom Analog False VacuumApr 16 2019We investigate the nonlinear dynamics of cold atom systems that can in principle serve as quantum simulators of false vacuum decay. The analog false vacuum manifests as a metastable vacuum state for the relative phase in a two-species Bose-Einstein condensate ... More
Experimental High-Dimensional Entanglement by Path IdentityApr 16 2019Versatile and high-brightness sources of high-dimensional entangled photon pairs are important for emerging quantum technologies such as secure quantum communication. Here, we experimentally demonstrate a new scalable method to create photon pairs carrying ... More
Kerdock Codes Determine Unitary 2-DesignsApr 16 2019The non-linear binary Kerdock codes are known to be Gray images of certain extended cyclic codes of length $N = 2^m$ over $\mathbb{Z}_4$. We show that exponentiating these $\mathbb{Z}_4$-valued codewords by $\imath \triangleq \sqrt{-1}$ produces stabilizer ... More
Broadband quadrature-squeezed vacuum and nonclassical photon number correlations from a nanophotonic deviceApr 16 2019We report the first demonstrations of both quadrature squeezed vacuum and photon number difference squeezing generated in an integrated nanophotonic device. Squeezed light is generated via strongly driven spontaneous four-wave mixing below threshold in ... More
Broadband quadrature-squeezed vacuum and nonclassical photon number correlations from a nanophotonic deviceApr 16 2019Apr 17 2019We report the first demonstrations of both quadrature squeezed vacuum and photon number difference squeezing generated in an integrated nanophotonic device. Squeezed light is generated via strongly driven spontaneous four-wave mixing below threshold in ... More
Engineering spin squeezing in a 3D optical lattice with interacting spin-orbit-coupled fermionsApr 16 2019One of the most important tasks in modern quantum science is to coherently control and entangle many-body systems, and to subsequently use these systems to realize powerful quantum technologies such as quantum-enhanced sensors. However, many-body entangled ... More
Quantum Statistical Enhancement of the Collective Performance of Multiple Bosonic EnginesApr 16 2019We consider an ensemble of indistinguishable quantum machines and show that quantum statistical effects can give rise to a genuine quantum enhancement of the collective thermodynamic performance. When multiple indistinguishable Bosonic work resources ... More
Measuring von Neumann entanglement entropies without wave functionsApr 16 2019We present a method to measure the von Neumann entanglement entropy of ground states of quantum many-body systems which does not require access to the system wave function. The technique is based on a direct thermodynamic study of entanglement Hamiltonians, ... More
Coherent Magneto-Optomechanical Signal Transduction and Long-Distance Phase-Shift KeyingApr 16 2019A transducer capable of converting quantum information stored as microwaves into telecom-wavelength signals is a critical piece of future quantum technology as it promises to enable the networking of quantum processors. Cavity optomechanical devices that ... More
Quasi-Exactly Solvable Scattering Problems, Exactness of the Born Approximation, and Broadband Unidirectional Invisibility in Two DimensionsApr 16 2019Achieving exact unidirectional invisibility in a finite frequency band has been an outstanding problem for many years. We offer a simple solution to this problem in two dimensions that is based on our solution to another more basic open problem of scattering ... More
Quantum Impurity Models coupled to Markovian and Non Markovian BathsApr 16 2019We develop a method to study quantum impurity models, small interacting quantum systems linearly coupled to an environment, in presence of an additional Markovian quantum bath, with a generic non-linear coupling to the impurity. We aim at computing the ... More
The geometric and topological interpretation of Berry phase on a torusApr 16 2019Illustration of the geometric and topological properties of Berry phase is often in an obscure and abstract language of fiber bundles. In this article, we demonstrate these properties with a lucid and concrete system whose parameter space is a torus. ... More
Bounds on bipartite entanglement from fixed marginalsApr 16 2019We discuss the problem of characterizing upper bounds on entanglement in a bipartite quantum system when only the reduced density matrices (marginals) are known. In particular, starting from the known two-qubit case, we propose a family of candidates ... More
Allowed and Forbidden Bipartite Correlations from Thermal StatesApr 16 2019The strong connection between correlations and quantum thermodynamics raises a natural question about the preparation of correlated quantum states from two copies of a thermal qubit. In this work we study the specific forms of allowed and forbidden bipartite ... More
Flag Additivity in Quantum Resource TheoriesApr 16 2019Quantum resource theories offer a powerful framework for studying various phenomena in quantum physics. Despite considerable effort has been devoted to developing a unified framework of resource theories, there are few common properties that hold for ... More
Oscillating nuclear electric dipole moment induced by axion dark matter produces atomic and molecular EDMApr 16 2019According to the Schiff theorem nuclear electric dipole moment (EDM) is completely shielded in a neutral atom by electrons. This makes a static nuclear electric dipole moment (EDM) unobservable. Interaction with the axion dark matter field generates nuclear ... More
Thermodynamic uncertainty relations from exchange fluctuation theoremsApr 16 2019Thermodynamic uncertainty relations (TURs) place strict bounds on the fluctuations of thermodynamic quantities in terms of the associated entropy production. In this work we identify the tightest (and saturable) matrix-valued TUR that can be derived from ... More