Latest in cond-mat.quant-gas

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Applying machine learning optimization methods to the production of a quantum gasAug 22 2019We apply three machine learning strategies to optimize the atomic cooling processes utilized in the production of a Bose-Einstein condensate (BEC). For the first time, we optimize both laser cooling and evaporative cooling mechanisms simultaneously. We ... More
Nests and Chains of Hofstadter ButterfliesAug 22 2019The \lq Hofstadter butterfly', a plot of the spectrum of an electron in a two-dimensional periodic potential with a uniform magnetic field, contains subsets which resemble small, distorted images of the entire plot. We show how the sizes of these sub-images ... More
Nonzero temperature dynamics of a repulsive two-component Fermi gasAug 22 2019We study spin-dipole oscillations of a binary fermionic mixture at nonzero temperatures. We apply the atomic-orbital method combined with the Monte Carlo technique based sampling to probe finite temperatures. Our results agree quantitatively with recent ... More
Exact results for the boundary energy of one-dimensional bosonsAug 22 2019We study bosons in a one-dimensional hard wall box potential. In the case of contact interaction, the system is exactly solvable by Bethe ansatz, as first shown by Gaudin in 1971. Although contained in the exact solution, the boundary energy for this ... More
Normal modes for N identical particles: A study of the evolution of collective behavior from few-body to many-bodyAug 21 2019Normal mode dynamics are ubiquitous underlying the motions of diverse systems from rotating stars to crystal structures. These behaviors are composed of simple collective motions of particles which move with the same frequency and phase, thus encapsulating ... More
Multimode probing of superfluid $\mathbf{^4He}$ by tuning forksAug 21 2019Flexural mode vibrations of miniature piezoelectric tuning forks (TF) are known to be highly sensitive to superfluid excitations and quantum turbulence in $\mathrm{^3He}$ and $\mathrm{^4He}$ quantum fluids, as well as to the elastic properties of solid ... More
Collective oscillations of a two-component Fermi gas on the repulsive branchAug 21 2019We calculate frequencies of collective oscillations of two-component Fermi gas that is kept on the repulsive branch of its energy spectrum. Not only is a paramagnetic phase explored, but also a ferromagnetically separated one. Both in-, and out-of-phase ... More
Effects of staggered Dzyaloshinskii-Moriya interactions in a quasi-two-dimensional Shastry-Sutherland modelAug 21 2019Frustrated quantum spin systems exhibit exotic physics induced by external magnetic field with anisotropic interactions. Here, we study the effect of non-uniform Dzyaloshinskii-Moriya (DM) interactions on a quasi-$2$D Shastry-Sutherland lattice using ... More
Prethermal Phases of Non-equilibrium Matter in Long-range Interacting SystemsAug 20 2019We prove the existence of non-equilibrium phases of matter in the prethermal regime of periodically-driven, long-range interacting systems, with power-law exponent $\alpha > d$, where $d$ is the dimensionality of the system. In this context, we predict ... More
Interactions and charge transfer dynamics of an Al$^+$ ion immersed in ultracold Rb and Sr atomsAug 20 2019Atomic clocks based on an Al$^+$ ion sympathetically cooled by a laser-cooled alkaline-earth ion have achieved unprecedented accuracy. Here, we investigate theoretically interactions and charge transfer dynamics of an Al$^+$ ion immersed in an ultracold ... More
Beyond mean-field corrections to the quasiparticle spectrum of superfluid Fermi gasesAug 20 2019We investigate the fermionic quasiparticle branch of superfluid Fermi gases in the BCS-BEC crossover and calculate the quasiparticle lifetime and energy shift due to its coupling with the collective mode. Close to the minimum of the branch the quasiparticles ... More
On the hydrodynamic formalism of the Gross-Pitaevskii fieldAug 19 2019We derive a canonical formalism for the hydrodynamic representation of the Gross-Pitaevskii field (nonlinear Schr\"odinger field), where the density and the phase of the condensate form a canonical pair of conjugate field variables. To do so, we treat ... More
Extreme fluctuations of entropies in quantum systemsAug 19 2019The intuition that we have about entropy -- coming largely from the Boltzmann entropy -- is that the maximum entropy state is very close to the equilibrium state, while low entropy is associated with highly non-equilibrium states. It this paper, we investigate ... More
Bosonic fractional quantum Hall states in driven optical latticesAug 19 2019Strong synthetic magnetic fields have been successfully implemented in periodically driven optical lattices. However, the interplay of the driving and interactions introduces detrimental heating, and for this reason it is still challenging to reach a ... More
Energetics and structural properties of two- and three-boson systems in the presence of 1D spin-orbit couplingAug 19 2019It was shown recently that the discrete scaling symmetry, which underlies the Efimov effect in the three identical boson system with two-body short-range interactions, survives when single-particle 1D spin-orbit coupling terms are added to the Hamiltonian. ... More
Phase-separated symmetry-breaking vortex-lattice in a binary Bose-Einstein condensateAug 19 2019We study spontaneous-symmetry-breaking circularly-asymmetric phase separation of vortex lattices in a rapidly rotating harmonically-trapped quasi-two-dimensional (quasi-2D) binary Bose-Einstein condensate (BEC) with repulsive inter- and intra-species ... More
Interacting Symmetry-Protected Topological Phases Out of EquilibriumAug 19 2019We show that the dynamics of generic isolated quantum systems admits a topological classification which captures universal features of many-body wavefunctions far from equilibrium. Specifically, we consider two short-ranged entangled wavefunctions to ... More
Non-Abelian gauge potential driven localization transition in quasiperiodic optical latticesAug 19 2019Gauge potential is an emergent concept in systems of ultracold atomic gases. Derived from quantum waves immersed in an \emph{Abelian} gauge, the quasiperiodic Aubry-Andre-Harper (AAH) model is a simple yet powerful Hamiltonian to study the Anderson localization ... More
Massive vortices in a binary mixture of Bose-Einstein condensatesAug 19 2019We thoroughly analyze a notable class of states peculiar to a bosonic repulsive binary mixture loaded in a rotating box-like circular trap, i.e. states where vortices in one species host the atoms of the other species, which thus play the role of massive ... More
Ferromagnetism in the SU($n$) Hubbard model with nearly flat-bandAug 17 2019We present rigorous results for the SU($n$) Fermi-Hubbard model on a one-dimensional Tasaki lattice. We first study the model with a flat band at the bottom of the single-particle spectrum and prove that the ground states exhibit SU($n$) ferromagnetism ... More
Non-spreading matter-wave packets in a ringAug 17 2019Non-spreading wave packets and matter-wave packets in ring traps both have attracted great research interests due to their miraculous physical properties and tempting applications for quite a long time. Here, we proved that there exists only one set of ... More
Dielectric breakdown of strongly correlated insulators in one dimension: Universal formula from non-Hermitian sine-Gordon theoryAug 16 2019Application of sufficiently strong electric fields to insulators induces finite currents and then the insulators become metallic. This phenomenon is called dielectric breakdown and known as a fundamental nonequilibrium and nonlinear transport phenomenon ... More
Parallel implementation of high-fidelity multi-qubit gates with neutral atomsAug 16 2019We report the implementation of universal two- and three-qubit entangling gates on neutral atom qubits encoded in long-lived hyperfine ground states. The gates are mediated by excitation to strongly interacting Rydberg states, and are implemented in parallel ... More
Parallel implementation of high-fidelity multi-qubit gates with neutral atomsAug 16 2019Aug 20 2019We report the implementation of universal two- and three-qubit entangling gates on neutral atom qubits encoded in long-lived hyperfine ground states. The gates are mediated by excitation to strongly interacting Rydberg states, and are implemented in parallel ... More
Dynamics of Hot Bose-Einstein Condensates: stochastic Ehrenfest relations for number and energy dampingAug 16 2019Describing high-temperature Bose gases poses a long-standing theoretical challenge. We present exact stochastic Ehrenfest relations for the stochastic projected Gross-Pitaevskii equation, including both number and energy damping mechanisms, and all projector ... More
An atomic array optical clock with single-atom readoutAug 15 2019Measuring time is central to all sciences. Currently, the most accurate and stable clocks are based on optical interrogation of either a single ion or an ensemble of neutral atoms confined in an optical lattice. Here we demonstrate a new optical clock ... More
Engineered Nearest-Neighbour Interactions with Doubly Modulated Optical LatticesAug 15 2019Optical lattice systems provide exceptional platforms for quantum simulation of many-body systems. We focus on the doubly modulated Bose-Hubbard model driven by both time-dependent on-site energy and interaction, and predict the emergence of the nearest ... More
Observation of Dynamical FermionizationAug 14 2019We observe dynamical fermionization, where the momentum distribution of a Tonks-Girardeau (T-G) gas of strongly interacting bosons in 1D evolves from bosonic to fermionic after its axial confinement is removed. The asymptotic momentum distribution after ... More
Emergent Spatial Structure and Entanglement Localization in Floquet Conformal Field TheoryAug 14 2019We study the energy and entanglement dynamics of $(1+1)$D conformal field theories (CFTs) under a Floquet drive with the sine-square deformed (SSD) Hamiltonian. Previous work has shown this model supports both a non-heating and a heating phase. Here we ... More
Global Symmetry and Maximal ChaosAug 14 2019In this note we study chaos in generic quantum systems with a global symmetry generalizing seminal work [arXiv : 1503.01409] by Maldacena, Shenker and Stanford. We conjecture a bound on chaos exponent in a thermodynamic ensemble at temperature $T$ and ... More
Quantum anomaly and thermodynamics of one-dimensional fermions with antisymmetric two-body interactionsAug 14 2019A system of two-species, one-dimensional fermions, with an attractive two-body interaction of the derivative-delta type, features a scale anomaly. In contrast to the well-known two-dimensional case with contact interactions, and its one-dimensional cousin ... More
Interaction Control of Ultracold Alkaline-Earth AtomsAug 14 2019Ultracold alkaline-earth atoms have now been widely explored for precision measurements and quantum simulation. Because of its unique atomic structure, alkaline earth atoms possess great advantages for quantum simulation and studying quantum many-body ... More
Scrambled Mean Field Approach to the Quantum Dynamics of Degenerate Bose GasesAug 13 2019We present a novel approach to modeling dynamics of trapped, degenerate, weakly interacting Bose gases beyond the mean field limit. We transform a many-body problem to the interaction representation with respect to a suitably chosen part of the Hamiltonian ... More
Pairing in two-dimensional Fermi gases with a coordinate-space potentialAug 13 2019In this work we theoretically study pairing in two-dimensional Fermi gases, a system which is experimentally accessible using cold atoms. We start by deriving the mean-field pairing gap equation for a coordinate-space potential with a finite interaction ... More
Criticality of Spin Systems with Weak Long-Range InteractionsAug 13 2019The study of critical properties of systems with long-range interactions has attracted in the last decades a continuing interest and motivated the development of several analytical and numerical techniques, in particular in connection with spin models. ... More
Frustrated orbital Feshbach resonances in a Fermi gasAug 13 2019The orbital Feshbach resonance (OFR) is a novel scheme for magnetically tuning the interactions in closed-shell fermionic atoms. Remarkably, unlike the Feshbach resonances in alkali atoms, the open and closed channels of the OFR are only very weakly detuned ... More
Tight-Binding Kondo Model and Spin-Exchange Collision Rate of Alkaline-Earth Atoms in a Mixed-Dimensional Optical LatticeAug 13 2019We study the ultracold fermionic alkaline-earth (like) atoms in the electronic $^1$S$_0$ state ($g$-state) and $^3$P$_0$ state ($e$-state), which are confined in a quasi-one-dimensional (quasi-1D) tube. In addition, in the axial direction, the $g$-atom ... More
Dark-State Optical Potential Barriers with Nanoscale SpacingAug 12 2019Optical potentials have been a versatile tool for the study of atomic motions and many-body interactions in cold atoms. Recently, optical subwavelength single barriers were proposed to enhance the atomic interaction energy scale, which is based on non-adiabatic ... More
Clustering of Four-Component Unitary FermionsAug 12 2019Ab initio nuclear physics tackles the problem of strongly interacting four-component fermions. The same setting could foreseeably be probed experimentally in ultracold atomic systems, where two- and three-component experiments have led to major breakthroughs ... More
Frustrated Quantum Magnetism with Bose Gases in Triangular Optical Lattices at Negative Absolute TemperaturesAug 12 2019We propose an experimental protocol to perform analog quantum simulation of frustrated antiferromagnetism with strong quantum fluctuations by using ultracold Bose gases in triangular optical lattices with isosceles anisotoropy of hoppings. Specifically, ... More
Floquet engineering of topological phases protected by emergent symmetries under resonant drivesAug 12 2019Aug 13 2019Floquet engineering is one of the most vigorous fields in periodically driven (Floquet) systems, with which we can control phases of matter usually by high-frequency drives. In this paper, with Floquet engineering by a combination of high-frequency drives ... More
Floquet engineering of topological phases protected by emergent symmetries under resonant drivesAug 12 2019Floquet engineering is one of the most vigorous fields in periodically driven (Floquet) systems, with which we can control phases of matter usually by high-frequency drives. In this paper, with Floquet engineering by a combination of high-frequency drives ... More
Many-body localization in XY spin chains with long-range interactions: An exact diagonalization studyAug 12 2019Aug 19 2019We investigate the transition from the many-body localized phase to the ergodic thermalized phase at an infinite temperature in an $XY$ spin chain with $L$ spins, which experiences power-law decaying interactions in the form of $V_{ij}\propto1/\left|i-j\right|^{\alpha}$ ... More
Many-body localization in XY spin chains with random long-range interactions: An exact diagonalization studyAug 12 2019We investigate the transition from many-body localization phase to ergodic thermalized phase at an infinite temperature in an $XY$ spin chain with $L$ spins, which experiences random power-law decaying interactions in the form of $V_{ij}\propto1/\ |i-j\ ... More
Tightening the Lieb-Robinson bound in locally-interacting systemsAug 12 2019The Lieb-Robinson (LR) bound rigorously shows that in quantum systems with short-range interactions, the maximum amount of information that travels beyond an effective "light cone" decays exponentially with distance from the light-cone front, which expands ... More
Tightening the Lieb-Robinson bound in locally-interacting systemsAug 12 2019Aug 19 2019The Lieb-Robinson (LR) bound rigorously shows that in quantum systems with short-range interactions, the maximum amount of information that travels beyond an effective "light cone" decays exponentially with distance from the light-cone front, which expands ... More
Many-body dynamical localization and thermalizationAug 11 2019We demonstrate dynamical localization in a generic setup of two weakly-coupled chaotic subsystems. The minimal subsystem of experimental interest is a 3-mode Bose-Hubbard trimer. We clarify the procedure for identification of a mobility edge in the chaotic ... More
Doublon dynamics of Bose-Fermi mixtures in optical latticesAug 10 2019We study the out-of-equilibrium dynamics of a dilute, lattice-confined Bose-Fermi mixture initialized in a highly excited state consisting of boson-fermion pairs (doublons) occupying single lattice sites. This system represents a paradigmatic case for ... More
Multiconfigurational time-dependent Hartree approaches for indistinguishable particlesAug 09 2019In this Colloquium, the wavefunction-based Multiconfigurational Time-Dependent Hartree approaches to the dynamics of indistinguishable particles (MCTDH-F for Fermions and MCTDH-B for Bosons) are reviewed. MCTDH-B and MCTDH-F or, together, MCTDH-X are ... More
Imaging the hydrodynamics of a single polaritonAug 09 2019Semiconductor devices are strong competitors in the race for the development of quantum computational systems. In this work, we interface two semiconductor building blocks of different dimensionality and with complementary properties: (1) a quantum dot ... More
Quantum fluctuations beyond the Gutzwiller approximation in the Bose-Hubbard modelAug 09 2019We develop a quantum many-body theory of the Bose-Hubbard model based on the canonical quantization of the action derived from a Gutzwiller mean-field ansatz. Capitalizing on the ability of this latter to describe both the Mott insulator and the superfluid ... More
Many-body dynamical localization in the kicked Bose-Hubbard chainAug 09 2019We show that a clean kicked Bose-Hubbard model exhibits a dynamically many-body localized phase. This phase is characterized by ergodicity breaking persisting in the thermodynamic limit: the system does not heat up to infinite temperature, whatever the ... More
Critical fluctuations at a many-body exceptional pointAug 08 2019Critical phenomena arise ubiquitously in various context of physics, from condensed matter, high energy physics, cosmology, to biological systems, and consist of slow and long-distance fluctuations near a phase transition or critical point. Usually, these ... More
Super Hamiltonian in superspace for incommensurate superlattices and quasicrystalsAug 08 2019Infinite quasiperiodic arrangements in space, such as quasicrystals, are typically described as projections of higher-dimensional periodic lattices onto the physical dimension. The concept of a reference higher-dimensional space, called a superspace, ... More
An experimental test of the geodesic rule proposition for the non-cyclic geometric phaseAug 08 2019The geometric phase due to the evolution of the Hamiltonian is a central concept in quantum physics, and may become advantageous for quantum technology. In non-cyclic evolutions, a proposition relates the geometric phase to the area bounded by the phase-space ... More
Cluster stability driven by quantum fluctuationsAug 08 2019By means of an accurate path-integral Monte Carlo we investigate a two-dimensional ensemble of particles interacting via a Lifshitz-Petrich-Gaussian potential. In particular, analysing structures described by a commensurate ratio between the two wave ... More
Systematic interpolatory ansatz for one-dimensional polaron systemsAug 07 2019We explore a new variational principle for studying one-dimensional quantum systems in a trapping potential. We focus on the Fermi polaron problem, where a single distinguishable impurity interacts through a contact potential with a background of identical ... More
Integrable model of a $p$-wave bosonic superfluidAug 07 2019We present an exactly-solvable $p$-wave pairing model for two bosonic species. The model is solvable in any dimension and it shows striking similarities with the $p+ip$ Richardson-Gaudin fermionic model. As the fermionic model, our bosonic counterpart ... More
Quantum Overlapping TomographyAug 07 2019It is now experimentally possible to entangle thousands of qubits, and efficiently measure each qubit in parallel in a distinct basis. To fully characterize an unknown entangled state of $n$ qubits, one requires an exponential number of measurements in ... More
Thermodynamics of spin-orbit coupled bosons in two dimensions from complex LangevinAug 07 2019We investigate the thermal properties of interacting spin-orbit coupled bosons with contact interactions in two spatial dimensions. To that end, we implement the complex Langevin method, motivated by the appearance of a sign problem, on a square lattice ... More
Thermodynamics of spin-orbit coupled bosons in two dimensions from complex LangevinAug 07 2019Aug 16 2019We investigate the thermal properties of interacting spin-orbit coupled bosons with contact interactions in two spatial dimensions. To that end, we implement the complex Langevin method, motivated by the appearance of a sign problem, on a square lattice ... More
Singlet Pathway to the Ground State of Ultracold Polar MoleculesAug 07 2019Starting from weakly bound Feshbach molecules, we demonstrate a two-photon pathway to the dipolar ground state of bi-alkali molecules that involves only singlet-to-singlet optical transitions. This pathway eliminates the search for a suitable intermediate ... More
In-medium bound states of two bosonic impurities in a one-dimensional Fermi gasAug 07 2019We investigate the ground-state energy of a one-dimensional Fermi gas with two bosonic impurities. First, we consider the case where impurity and gas atoms have equal masses. The impurity-impurity two-body interaction is identical to the atom-impurity ... More
Nonlinear dynamics of Josephson vortices in merging superfluid ringsAug 07 2019We consider merger of two parallel toroidal atomic Bose-Einstein condensates with different vorticities in a three-dimensional (3D) trap. In the tunnel-coupling regime, Josephson vortices (rotational fluxons) emerge in the barrier between the superflows. ... More
Improved low-dimensional wave equations for cigar-shaped and disk-shaped dipolar Bose-Einstein condensatesAug 06 2019Within the formalism of the Gross-Pitaevskii equation, we derive effective one- and two-dimensional equations for cigar- and pancake-shaped dipolar Bose-Einstein condensates with arbitrary polarization angle. These are based on an ansatz for the condensate ... More
Hawking temperature in dispersive media: Analytical and numerical studyAug 06 2019In the context of analog gravity the Hawking effect can be generalized to domains outside astrophysics. Arguably, the most successful systems for this analogy have been so far the sonic and the optical ones. However, problems arise in the analog systems ... More
Superfluidity fraction of few bosons in an annular geometry in the presence of a rotating weak linkAug 06 2019We report a beyond mean-field calculation of mass current and superfluidity fraction for a system of few bosons confined in a ring geometry in the presence of a rotating weak link induced by a potential barrier. We apply the Multiconfiguration Hartree ... More
$\mathbb{Z}_n$ Solitons in Intertwined Topological Phases: From Boson Fractionalization to a Generalized Bulk-Defect CorrespondenceAug 06 2019Topological phases of matter can support fractionalized quasi-particles localized at topological defects. The current understanding of these exotic excitations, based on the celebrated bulk-defect correspondence, typically relies on crude approximations ... More
One-Particle Density Matrix for a Quantum Gas in the Box GeometryAug 06 2019We have analytically obtained 1-particle density matrices for ideal Bose and Fermi gases in 3-D box geometries for the entire range of temperature. We also have obtained quantum cluster expansions of the grand free energies in closed forms for the same ... More
Floating Phases in One-Dimensional Rydberg Ising ChainsAug 06 2019We report on the quantitative ground state phase diagram of a van der Waals interacting chain of Rydberg atoms. These systems are known to host crystalline phases locked to the underlying lattice as well as a gapped, disordered phase. We locate and characterize ... More
Non-Hermitian Floquet topological phases in the double-kicked rotorAug 06 2019Dynamical kicking systems possess rich topological structures. In this work, we study Floquet states of matter in a non-Hermitian extension of double kicked rotor model. Under the on-resonance condition, we find various non-Hermitian Floquet topological ... More
Reservoir engineering of Cooper-pair-assisted transport with cold atomsAug 06 2019We show how Cooper-pair-assisted transport, which describes the stimulated transport of electrons in the presence of Cooper-pairs, can be engineered and controlled with cold atoms, in regimes that are difficult to access for condensed matter systems. ... More
Electric-circuit simulation of the Schrödinger equation and non-Hermitian quantum walksAug 06 2019Recent progress has witnessed that various topological physics can be simulated by electric circuits under alternating current. However, it is still a nontrivial problem if we may simulate the dynamics subject to the Schr\"{o}dinger equation based on ... More
Chaos induced breakdown of Bose-Hubbard modelingAug 06 2019We show that the Bose-Hubbard approximation fails due to the emergence of chaos, even when excited modes are far detuned and the standard validity condition is satisfied. This is formally identical to the Melnikov-Arnold analysis of the stochastic pump ... More
Information measures for a local quantum phase transition:Lattice bosons in a one-dimensional harmonic trapAug 05 2019We study ground-state quantum entanglement in the one-dimensional Bose-Hubbard model in the presence of a harmonic trap. We focus on two transitions that occur upon increasing the characteristic particle density: the formation of a Mott insulating domain ... More
Emergent Quasicrystalline Symmetry in Light-Induced Quantum Phase TransitionsAug 05 2019The discovery of quasicrystals with crystallographically forbidden rotational symmetries has changed the notion of the ordering in materials, yet little is known about the dynamical emergence of such exotic forms of order. Here we theoretically study ... More
Provable bounds for the Korteweg-de Vries reduction in multi-component Nonlinear Schrodinger EquationAug 05 2019We study the dynamics of multi-component Bose gas described by the Vector Nonlinear Schrodinger Equation (VNLS), aka the Vector Gross--Pitaevskii Equation (VGPE) . Through a Madelung transformation, the VNLS can be reduced to coupled hydrodynamic equations ... More
Microwave shielding of ultracold polar molecules with imperfectly circular polarizationAug 05 2019We investigate the use of microwave radiation to produce a repulsive shield between pairs of ultracold polar molecules and prevent collisional losses that occur when molecular pairs reach short range. We carry out coupled-channels calculations on RbCs+RbCs ... More
Designing Arbitrary One-dimensional Potentials on an Atom ChipAug 05 2019We use laser light shaped by a digital micro-mirror device to realize arbitrary optical dipole potentials for one-dimensional (1D) degenerate Bose gases of 87Rb trapped on an atom chip. Superposing optical and magnetic potentials combines the high flexibility ... More
Effects of quantum fluctuations on the dynamics of dipolar Bose polaronsAug 04 2019We study the dynamics of dipolar Bose polarons in the presence of the normal and anomalous fluctuations using the time-dependent Hartree-Fock-Bogoliubov theory. The density profiles of the condensate, the anomalous component and the impurity are deeply ... More
Tunneling vortex dynamics in linearly coupled Bose-Hubbard ringsAug 04 2019The quantum dynamics of population-balanced fractional vortices and population-imbalanced vortices in an effective two-state bosonic system, made of two coupled discrete circuits with few sites, is addressed within the Bose-Hubbard model. % We show that ... More
Finite-temperature dynamics of a Tonks-Girardeau gas in a frequency-modulated harmonic trapAug 04 2019We study the out-of-equilibrium dynamics of a finite-temperature harmonically trapped Tonks-Girardeau gas induced by periodic modulation of the trap frequency. We give explicit exact solutions for the real-space density and momentum distributions of this ... More
Decay of a Quantum KnotAug 04 2019We experimentally study the dynamics of quantum knots in a uniform magnetic field in spin-1 Bose-Einstein condensates. The knot is created in the polar magnetic phase, which rapidly undergoes a transition towards the ferromagnetic phase in the presence ... More
Non-Hermitian Topological Anderson InsulatorsAug 03 2019Non-Hermitian systems can exhibit unique topological and localization properties. Here we elucidate the non-Hermitian effects on disordered topological systems by studying a non-Hermitian disordered Su-Schrieffer-Heeger model with nonreciprocal hoppings. ... More
Free Fermions with a Localized SourceAug 02 2019We study an open quantum system of free fermions on an infinite lattice coupled to a localized particle source. In the long time limit, the total number of fermions in the system increases linearly with growth rate dependent on the lattice geometry and ... More
Critical response of a quantum van der Pol oscillatorAug 02 2019Classical nonequilibrium systems close to a dynamical critical point are known to exhibit a strongly nonlinear response, resulting in very high sensitivity to weak external perturbations. This attribute is key to the operation of important biological ... More
Fluctuation dynamics of an open dye microcavity photon Bose-Einstein condensateAug 02 2019Bosonic gases coupled to a particle reservoir have proven to support a regime of operation where Bose-Einstein condensation coexists with unusually large particle-number fluctuations. Experimentally, this situation has been realized with two-dimensional ... More
Three-dimensional trapping of individual Rydberg atoms in ponderomotive bottle beam trapsAug 02 2019We demonstrate three-dimensional trapping of individual Rydberg atoms in holographic optical bottle beam traps. Starting with cold, ground-state $^{87}$Rb atoms held in standard optical tweezers, we excite them to $nS_{1/2}$, $nP_{1/2}$, or $nD_{3/2}$ ... More
Geometric contribution to the Goldstone mode in spin-orbit coupled Fermi superfluidsAug 02 2019The so-called quantum metric tensor is a band-structure invariant whose measure corresponds to the quantum distance between nearby states in the Hilbert space, characterizing the geometry of the underlying quantum states. In the context of spin-orbit ... More
Effective expression of the Lee-Huang-Yang energy functional for heteronuclear mixturesAug 02 2019We show that the Lee-Huang-Yang (LHY) energy functional for a heteronuclear Bose mixture can be accurately approximated by an expression that has the same functional form as in the homonuclear case. It is characterized by two exponents, which can be treated ... More
Observation of Quantum Droplets in a Heteronuclear Bosonic MixtureAug 02 2019We report on the formation of heteronuclear quantum droplets in an attractive bosonic mixture of 41K and 87Rb. We observe long-lived self-bound states, both in free space and in an optical waveguide. In the latter case, the dynamics under the effect of ... More
Application of renormalized RPA to polarized Fermi gasesAug 01 2019We consider a spin imbalanced Fermi gas at zero temperature in the normal phase and located on the BCS side of the BCS-BEC crossover. We compute the critical polarization for pairing, the correlated occupation numbers and the contact in the framework ... More
Correlations and dynamics of tunnel-coupled one-dimensional Bose gasesAug 01 2019We present a series of experiments performed with two ultracold one-dimensional Bose gases (rubidium atoms) in a double well potential. Employing matter-wave interference, we can measure the spatially resolved phase difference between the two gases and ... More
Many-body-localization induced protection of symmetry-protected topological order in a XXZ spin modelAug 01 2019There is a qualitative conjecture by Huse et al. [Phys. Rev. B 88, 014206 (2013)], and Chandran et al. [Phys. Rev. B 89,144201 (2014)]: Localization protects quantum order of groundstate even in high excited eigenstates. In this work, we show a concrete ... More
Pair correlation of atoms scattered from colliding Bose-Einstein quasicondensatesAug 01 2019A collision of Bose-Einstein condensates is a useful source of single nonclassically correlated pairs of atoms. Here, we consider elastic scattering of atoms from elongated clouds taking into account an effective, finite duration of the collision due ... More
Semiclassical approximation to virial coefficients beyond the leading orderAug 01 2019We extend the calculation of virial coefficients of Fermi gases in the semiclassical approximation to next-to- and next-to-next-to-leading orders for $b_2$, $b_3$, $b_4$, and $b_5$. Our results feature relationships between interaction-induced changes ... More
Strongly correlated quantum droplets in quasi-1D dipolar Bose gasJul 31 2019We exploit a few- to many-body approach to study strongly interacting dipolar bosons in the quasi-one-dimensional system. The dipoles attract each other while the short range interactions are repulsive. Solving numerically exactly the multi-atom Schr\"{o}dinger ... More
Third- and fourth-order virial coefficients of harmonically trapped fermions in a semiclassical approximationJul 31 2019Using a leading-order semiclassical approximation, we calculate the third- and fourth-order virial coefficients of nonrelativistic spin-1/2 fermions in a harmonic trapping potential in arbitrary spatial dimensions, and as functions of temperature, trapping ... More
Direct Observation of Ultracold Bimolecular ReactionsJul 31 2019Chemical reactions result in the conversion of reactants to products through an intermediate state or a transition state. Unambiguous identifications of and investigations of chemical reactions are thus most complete when detecting all of the involved ... More
Measuring the time a tunnelling atom spends in the barrierJul 31 2019Tunnelling is one of the most paradigmatic and evocative phenomena of quantum physics, underlying processes such as photosynthesis and nuclear fusion, as well as devices ranging from SQUID magnetometers to superconducting qubits for quantum computers. ... More