Latest in cond-mat.quant-gas

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Absence of superfluidity in 2D dipolar Bose striped crystalsJun 13 2019We present results of computer simulations at low temperature of a two-dimensional system of dipolar bosons, with dipole moments aligned at an arbitrary angle with respect to the direction perpendicular to the plane. The phase diagram includes a homogeneous ... More
Pump driven normal-to-excitonic insulator transition: Josephson oscillations and signatures of BEC-BCS crossover in time-resolved ARPESJun 13 2019We consider a ground-state wide-gap band insulator turning into a nonequilibrium excitonic insulator (NEQ-EI) upon visiting properly selected and physically relevant highly excited states. The NEQ-EI phase, characterized by self-sustained oscillations ... More
Collective excitations and tunneling dynamics in long bosonic Josephson junctionsJun 13 2019We investigate the low-energy dynamics of two coupled anisotropic Bose-Einstein condensates forming a long Josephson junction. The theoretical study is performed in the framework of the two-dimensional Gross-Pitaevskii equation and the Bogoliubov-de Gennes ... More
Controllable Finite-Momenta Dynamical Quasicondensation in the Periodically Driven One-Dimensional Fermi-Hubbard ModelJun 12 2019In the strongly interacting limit of the Hubbard model localized double-occupancies form effective hard-core bosonic excitations, called a doublons, which are long-lived due to energy conservation. Using time-dependent density-matrix renormalisation group ... More
Strongly Correlated Quantum Gas Prepared by Direct Laser CoolingJun 12 2019We create a one-dimensional strongly correlated quantum gas of $^{133}$Cs atoms with attractive interactions by direct laser cooling in 300~ms. After compressing and cooling the optically trapped atoms to the vibrational ground state along two tightly ... More
Outcoupling from a Bose-Einstein condensate in the strong-field limitJun 12 2019Atoms can be extracted from a trapped Bose-Einstein condensate (BEC) by driving spin-flips to untrapped states. The coherence properties of the BEC are transfered to the released atoms, creating a coherent beam of matter refered to as an atom laser. In ... More
Many-body topological invariants from randomized measurementsJun 12 2019The classification of symmetry-protected topological (SPT) phases in one dimension has been recently achieved, and had a fundamental impact in our understanding of quantum phases in condensed matter physics. In this framework, SPT phases can be identified ... More
The low-energy Goldstone mode in a trapped dipolar supersolidJun 11 2019A supersolid is a counter-intuitive state of matter that combines the frictionless flow of a superfluid with the crystal-like periodic density modulation of a solid. Since the first prediction in the 1950s, experimental efforts to realize this state have ... More
Chiral 2D p-wave superfluid from s-wave pairing in the BEC limitJun 11 2019Two-dimensional spin-orbit-coupled Fermi gases subject to s-wave pairing can be driven into a topological phase by increasing the Zeeman spin splitting beyond a critical value. In the topological regime, the system exhibits the hallmarks of chiral p-wave ... More
An optimized twist angle to find the twist-averaged correlation energy applied to the uniform electron gasJun 11 2019We explore an alternative to twist averaging in order to obtain more cost-effective and accurate extrapolations to the thermodynamic limit (TDL) for coupled cluster doubles (CCD) calculations. We seek a single twist angle to perform calculations at, instead ... More
The structure of chaotic eigenstates and their entanglement entropyJun 10 2019We consider a chaotic many-body system that is split into two subsystems, with an interaction along their mutual boundary, and study the entanglement properties of an energy eigenstate with nonzero energy density. When the two subsystems have nearly equal ... More
Phase diagram of Rydberg-dressed Fermi gas in two dimensionsJun 10 2019Rydberg-dressed ultracold Fermi gas is one of the latest quantum many-body systems where the sign, strength, and range of the interaction can be controlled experimentally. The interaction in momentum space has a negative minimum at $q_c$ inversely proportional ... More
How much entanglement can be created in a closed system?Jun 10 2019In a closed system, the total number of particles is fixed. We ask how much does this conservation law restricts the amount of entanglement that can be created. We derive a tight upper bound on the bipartite entanglement entropy in closed systems, and ... More
Complexity phase diagram for interacting and long-range bosonic HamiltoniansJun 10 2019Recent years have witnessed a growing interest in topics at the intersection of many-body physics and complexity theory. Many-body physics aims to understand and classify emergent behavior of systems with a large number of particles, while complexity ... More
Two-dimensional non-Hermitian topological phases induced by asymmetric hopping in a one-dimensional superlatticeJun 10 2019Non-Hermitian systems can host novel topological states with novel topological invariants and bulk-edge correspondences that are distinct from conventional Hermitian systems. Here we show that two unique classes of non-Hermitian 2D topological phases, ... More
Mass-energy equivalence in harmonically trapped particlesJun 10 2019Precise understanding of the dynamics of trapped particles is crucial for nascent quantum technologies, including atomic clocks and quantum simulators. Here we present a framework to systematically include quantum effects arising from the mass-energy ... More
Quantum supremacy with analog quantum processors for material science and machine learningJun 10 2019Quantum supremacy is the ability of quantum processors to outperform classical computers at certain tasks. In digital random quantum circuit approaches for supremacy, the output distribution produced is described by the Porter-Thomas (PT) distribution. ... More
Mass-imbalance induced structures of binary atomic mixtures in box potentialsJun 09 2019We consider the ground states of binary atomic boson-boson and fermion-fermion mixtures confined in one-dimensional box potentials by simulating the systems using few-body models with delta-function interactions and many-body models with density-density ... More
Behavior of the relativistic Bose gas in a film geometry:\\ Exact results for the free energy and the Casimir forceJun 08 2019Within a known three-dimensional model of relativistic Bose gas that takes into account the existence of both particles and antiparticles, we derive exact expressions for the behavior of the free energy, excess free energy and the Casimir force for the ... More
Synthesis and Observation of Non-Abelian Gauge Fields in Real SpaceJun 08 2019Gauge fields, real or synthetic, are crucial for understanding and manipulation of physical systems. The associated geometric phases can be measured, for example, from the Aharonov--Bohm interference. So far, real-space realizations of gauge fields have ... More
Homogeneous Floquet time crystal protected by gauge invarianceJun 07 2019We show that homogeneous lattice gauge theories can realize nonequilibrium quantum phases with long-range spatiotemporal order protected by gauge invariance instead of disorder. We study a kicked $\mathbb{Z}_2$-Higgs gauge theory and find that it breaks ... More
Dicke subradiance and thermal decoherenceJun 07 2019Subradiance is the cooperative inhibition of the radiation by several emitters coupled to the same electromagnetic modes. It has been predicted by Dicke in 1954 and only recently observed in cold atomic vapors. Here we address the question to what extend ... More
Collective oscillations of a Bose-Einstein condensate induced by a vortex ringJun 07 2019We study the collective oscillations of three-dimensional Bose-Einstein condensates (BECs) excited by a vortex ring. We identify independent, integrated, and stationary modes of the center-of-mass oscillation of the condensate with respect to the vortex ... More
Supersolid symmetry breaking from compressional oscillations in a dipolar quantum gasJun 06 2019The existence of a paradoxical supersolid phase of matter, possessing the apparently incompatible properties of crystalline order and superfluidity, was predicted 50 years ago. Solid helium was the natural candidate, but there supersolidity has not been ... More
Quantum Approximate Optimization with a Trapped-Ion Quantum SimulatorJun 06 2019Quantum computers and simulators may offer significant advantages over their classical counterparts, providing insights into quantum many-body systems and possibly solving exponentially hard problems, such as optimization and satisfiability. Here we report ... More
Quantum quench in PT-symmetric Luttinger liquidJun 06 2019A Luttinger liquid (LL) describes low energy excitations of many interacting 1D systems, and exhibits universal behaviour both in and out of equilibrium. We analyze its behaviour in the non-hermitian realm after quantum quenching to a PT-symmetric LL ... More
Reaching the continuum limit in finite-temperature ab initio field-theory computations in many-fermion systemsJun 05 2019Finite-temperature, grand-canonical computations based on field theory are widely applied in areas including condensed matter physics, ultracold atomic gas systems, and lattice gauge theory. However, these calculations have computational costs scaling ... More
Exceptional points and the topology of quantum many-body spectraJun 05 2019We show that in a generic, ergodic quantum many-body system the interactions induce a non-trivial topology for an arbitrarily small non-hermitean component of the Hamiltonian. This is due to an exponential-in-system-size proliferation of exceptional points ... More
Memories of initial states and density imbalance in dynamics of interacting disordered systemsJun 05 2019We study the dynamics of one and two dimensional disordered lattice bosons/fermions initialized to a Fock state with a pattern of $1$ and $0$ particles on $A$ and ${\bar A}$ sites. For non-interacting systems we establish a universal relation between ... More
Superfluid Phase Transitions and Effects of Thermal Pairing Fluctuations in Asymmetric Nuclear MatterJun 05 2019We investigate superfluid phase transitions of asymmetric nuclear matter at finite temperature ($T$) and density ($\rho$) with a low proton fraction ($Y_{\rm p} \le 0.2$) which is relevant to the inner crust and outer core of neutron stars. A strong-coupling ... More
Multimode collective scattering of light in free space by a cold atomic gasJun 05 2019We have studied collective recoil lasing by a cold atomic gas, scattering photons from an incident laser into many radiation modes in free space. The model consists of a system of classical equations for the atomic motion of N atoms, where the radiation ... More
Neutron matter at the interface(s): from interactions to ab initio and from there to phenomenologyJun 04 2019Neutron matter is interesting both as an extension of terrestrial nuclear physics and due to its significance for the study of neutron stars. In this work, after some introductory comments on nuclear forces, nuclear ab initio theory, and nuclear phenomenology, ... More
Generalized hydrodynamics with space-time inhomogeneous interactionsJun 04 2019We provide a new hydrodynamic framework to describe out-of-equilibrium integrable systems with space-time inhomogeneous interactions. Our result builds up on the recently-introduced Generalized Hydrodynamics (GHD). The method allows to analytically describe ... More
Mixing-demixing and spontaneous symmetry breaking in trapped Bose-Fermi mixtures: Weak-coupling to unitarity crossoverJun 04 2019We study numerically mixing-demixing and spontaneous symmetry breaking in Bose-Fermi mixtures in spherically-symmetric and quasi-one-dimensional traps while the intra-species Bose and Fermi interactions are varied from weak-coupling to strong-coupling ... More
Quantum unbinding near a zero temperature liquid-gas transitionJun 04 2019We discuss the quantum phase transition from a liquid to a gaseous ground state in a Bose fluid with increasing strength of the zero point motion. It is shown that in the zero pressure limit, the two different ground states are separated by a quantum ... More
Dynamics of the creation of a rotating Bose-Einstein condensate by two-photon Raman transition using Laguerre-Gaussian pulseJun 03 2019We examine the dynamics associated with the creation of a vortex in a Bose-Einstein condensate (BEC), from another nonrotating BEC using two-photon Raman transition with Gaussian (G) and Laguerre-Gaussian (LG) laser pulses. In particular, we consider ... More
Strong and Weak Many-Body LocalizationsJun 03 2019Many aspects of many-body localization (MBL), including dynamic classification of MBL phases, remain elusive. Here, by performing real-space renormalization group (RSRG) analysis we propose that there are two distinct types of MBL phases: "strong MBL" ... More
Single-atom quantum probes for ultracold gases using nonequilibrium spin dynamicsJun 03 2019Quantum probes are atomic-sized devices mapping information of their environment to quantum mechanical states. By improving measurements and at the same time minimizing perturbation of the environment, they form a central asset for quantum technologies. ... More
Investigation of 3D-Quantized Ring Vortices in Rotating Coupled Atom-Molecular BECJun 01 2019We study the coupled atom-molecular quantized ring vortices of 87Rb Bose-Einstein Condensates (BEC) trapped in a rotating three dimensional (3D) anisotropic cylindrical trap both in time independent and time-dependent Gross-Pitaevskii approaches. For ... More
Periodically Driven Many-Body Systems: A Floquet Density Matrix Renormalization Group StudyMay 31 2019Driving a quantum system periodically in time can profoundly alter its long-time correlations and give rise to exotic quantum states of matter. The complexity of the combination of many-body correlations and dynamic manipulations has the potential to ... More
Time-Resolved Observation of Spin-Charge Deconfinement in Fermionic Hubbard ChainsMay 31 2019Elementary particles such as the electron carry several quantum numbers, for example, charge and spin. However, in an ensemble of strongly interacting particles, the emerging degrees of freedom can fundamentally differ from those of the individual constituents. ... More
Protected cat states from kinetic driving of a boson gasMay 31 2019We investigate the behavior of a one-dimensional Bose-Hubbard gas in both a ring and a hard-wall box, whose kinetic energy is made to oscillate with zero time-average, which suppresses first-order particle hopping. For intermediate and large driving amplitudes ... More
Protected cat states from kinetic driving of a boson gasMay 31 2019Jun 07 2019We investigate the behavior of a one-dimensional Bose-Hubbard gas in both a ring and a hard-wall box, whose kinetic energy is made to oscillate with zero time-average, which suppresses first-order particle hopping. For intermediate and large driving amplitudes ... More
Spin and charge correlations across the metal-to-insulator crossover in the half-filled $2d$ Hubbard modelMay 30 2019The $2d$ Hubbard model with nearest-neighbour hopping on the square lattice and an average of one electron per site is known to undergo an extended crossover from metallic to insulating behavior driven by proliferating antiferromagnetic correlations. ... More
Study of counterintuitive transport properties in the Aubry-André-Harper model via entanglement entropy and persistent currentMay 30 2019The single particle eigenstates of the Aubry-Andr\'e-Harper model are known to show a delocalization-localization transition at a finite strength of the quasi-periodic disorder. In this work, we point out that an intimate relationship exists between the ... More
Discrete Time CrystalsMay 30 2019Experimental advances have allowed for the exploration of nearly isolated quantum many-body systems whose coupling to an external bath is very weak. A particularly interesting class of such systems is those which do not thermalize under their own isolated ... More
Crystalline droplets with emergent topological color-charge in many-body systems with sign-changing interactionsMay 30 2019We introduce a novel type of self-bound droplet which carries an emergent color-charge. We consider a system of particles hopping on a lattice and interacting via a commensurately sign-changing potential which is attractive at short range. The droplet ... More
Dissipation induced non-stationarity in a quantum gasMay 30 2019Non-stationary long-time dynamics was recently observed in a driven two-component Bose-Einstein condensate coupled to an optical cavity [N. Dogra, et al. arXiv:1901.05974] and analyzed in mean-field theory. We provide the full solution of the underlying ... More
Slow quenches in Chern insulator ribbonsMay 29 2019We investigate slow quenches in Chern insulators in ribbon geometry. We consider the Qi-Wu-Zhang model and slowly ramp the parameters (large time of the quench $\tau$) from a non-topological (Chern number = 0) to a topological regime (Chern number $\ne$ ... More
Magnetic phases of orbital bipartite optical latticesMay 29 2019In the Hamburg cold atom experiment with orbital states in an optical lattice, $s$- and $p$-orbital atomic states hybridize between neighbouring sites. In this work we show how this alternation of sites hosting $s$- and $p$-orbital states gives rise to ... More
Directional Goldstone waves in polariton condensates close to equilibriumMay 29 2019Quantum fluids of light are realized in semiconductor microcavities by exciton-polaritons, solid-state quasi-particles with a light mass and sizeable interactions. Here, we use the microscopic analogue of oceanographic techniques to measure the excitation ... More
Quantitative analysis of $p$-wave three-body losses via cascade processMay 29 2019We describe the three-body loss coefficient of identical fermions with $p$-wave interactions using a set of rate equations in which three-body recombination happens via an indirect process. Our theoretical treatment explains experimental results just ... More
Variational Approach to Many-Body Problems Incorporating Many-Body Effects at Finite TemperatureMay 29 2019We develop a variational approach at finite temperature that incorporates many-body correlation self-consistently. The grand potential is constructed in terms of Green's function expressed by the variational parameters. We apply this formalism to weakly ... More
Quantum entropic self-localization with ultracold fermionsMay 28 2019We study a driven, spin-orbit coupled fermionic system in a lattice at the resonant regime where the drive frequency equals the Hubbard repulsion, for which non-trivial constrained dynamics emerge at fast timescales. An effective density-dependent tunneling ... More
Quantum Cluster QuasicrystalsMay 28 2019Quasicrystals remain among the most intriguing materials in physics and chemistry. Their structure results in many unusual properties including anomalously low friction as well as poor electrical and thermal conductivity but it also supports superconductivity, ... More
Disorder-induced Chern insulator in Harper-Hofstadter-Hatsugai modelMay 28 2019In this paper we study effects of disorder for topological Chern insulating phase in the Harper-Hofstadter-Hatsugai model. The model with half flux has bulk-band gap and thus exhibit non-trivial topological phase. We consider two typical types of disorder: ... More
Purity oscillations in coupled Bose-Einstein condensatesMay 28 2019It is shown that the distinct oscillations of the purity of the single-particle density matrix for many-body open quantum systems with balanced gain and loss reported by Dast et al. [Phys. Rev. A 93, 033617 (2016)] can also be found in closed quantum ... More
Coherent backaction between spins and an electronic bath: Non-Markovian dynamics and low temperature quantum thermodynamic electron coolingMay 27 2019We provide a general analytical framework for calculating the dynamics of a spin system in contact with a bath beyond the Markov approximation. The approach is based on a systematic expansion of the Nakashima-Zwanzig master equation in the weak-coupling ... More
Collective excitations in two-dimensional SU($N$) Fermi gases with tunable spinMay 26 2019We measure collective excitations of a harmonically trapped two-dimensional (2D) SU($N$) Fermi gas of $^{173}$Yb confined to a stack of layers formed by a one-dimensional optical lattice. Quadrupole and breathing modes are excited and monitored in the ... More
Two-body bound state of ultracold Fermi atoms with two-dimensional spin-orbit couplingMay 26 2019In a recent experiment, a two-dimensional spin-orbit coupling (SOC) was realized for fermions in the continuum [Nat. Phys. 12, 540 (2016)], which represents an important step forward in the study of synthetic gauge field using cold atoms. In the experiment, ... More
Observation of quantum depletion in a nonequilibrium exciton-polariton condensateMay 25 2019The property of superfluidity, first discovered in liquid 4He, is closely related to the Bose-Einstein condensation (BEC) of interacting bosons1. However, even at zero temperature, when the whole bosonic quantum liquid would become superfluid, only a ... More
Observation of quantum depletion in a nonequilibrium exciton-polariton condensateMay 25 2019May 31 2019The property of superfluidity, first discovered in liquid 4He, is closely related to the Bose-Einstein condensation (BEC) of interacting bosons. However, even at zero temperature, when the whole bosonic quantum liquid would become superfluid, only a fraction ... More
P-band induced self-organization and dynamics with repulsively driven ultracold atoms in an optical cavityMay 24 2019We investigate a Bose-Einstein condensate strongly coupled to an optical cavity via a repulsive optical lattice. We detect a stable self-ordered phase in this regime, and show that the atoms order through an antisymmetric coupling to the P-band of the ... More
Analytical treatment of the interaction quench dynamics of two bosons in a two-dimensional harmonic trapMay 24 2019We investigate the quantum dynamics of two bosons, trapped in a two-dimensional harmonic trap, upon quenching arbitrarily their interaction strength thereby covering the entire energy spectrum. Utilizing the exact analytical solution of the stationary ... More
Emission of twin jets from a driven matter-wave soliton in a quasi-one-dimensional geometryMay 24 2019The modulation of the interaction between the atoms in a matter-wave soliton in a quasi-one-dimensional optical trap triggers an emission of correlated atom jets. We characterize the dependence of jet properties on the frequency, amplitude and length ... More
Thermalization of a Lipkin-Meshkov-Glick model coupled to a bosonic bathMay 24 2019We derive a Lindblad master equation that approximates the dynamics of a Lipkin-Meshkov-Glick (LMG) model weakly coupled to a bosonic bath. By studying the time evolution of operators under the adjoint master equation we prove that, for large system sizes, ... More
Two-dimensional repulsive Fermi polarons with short and long-range interactionsMay 24 2019We study the repulsive polaron problem in a two-component two-dimensional system of fermionic atoms. We use two different interaction models: a short-range (hard-disk) potential and a dipolar potential. In our approach, all the atoms have the same mass ... More
Can three-body recombination purify a quantum gas?May 23 2019Three-body recombination in quantum gases is traditionally associated with heating, but it was recently found that it can also cool the gas. We show that in a partially condensed three-dimensional homogeneous Bose gas three-body loss could even purify ... More
Rotating binary Bose-Einstein condensates and vortex clusters in quantum dropletsMay 23 2019Quantum droplets may form out of a gaseous Bose-Einstein condensate, stabilized by quantum fluctuations beyond mean field. We show that multiple singly-quantized vortices may form in these droplets at moderate angular momenta in two dimensions. Droplets ... More
Efficient variational approach to dynamics of a spatially extended bosonic Kondo modelMay 23 2019We develop an efficient variational approach to studying dynamics of a localized quantum spin coupled to a bath of mobile spinful bosons. We use parity symmetry to decouple the impurity spin from the environment via a canonical transformation and reduce ... More
Transition from the mean-field to the bosonic Laughlin state in a rotating Bose-Einstein condensateMay 23 2019We consider a weakly-interacting Bose-Einstein condensate that rotates in either a harmonic, or a weakly-anharmonic trapping potential. Performing numerical calculations, we investigate the behaviour of the gas in these two cases as the angular momentum, ... More
Exact perturbative results for the Lieb-Liniger and Gaudin-Yang modelsMay 23 2019May 28 2019We present a systematic procedure to extract the perturbative series for the ground state energy density in the Lieb-Liniger and Gaudin-Yang models, starting from the Bethe ansatz solution. This makes it possible to calculate explicitly the coefficients ... More
Resurgence for superconductorsMay 23 2019An important non-perturbative effect in quantum physics is the energy gap of superconductors, which is exponentially small in the coupling constant. A natural question is whether this effect can be incorporated in the theory of resurgence. In this paper ... More
Waves in a Bose-Einstein condensate of atoms with a dipole momentMay 23 2019Based on the modified Gross-Pitaevskii equation for atoms with intrinsic dipole moments which accounts for the relaxation of a condensate, the dipole-dipole interaction and the interaction of atoms with the electromagnetic field, the propagation of the ... More
Symmetry-protected localized states at defects in non-Hermitian systemsMay 22 2019Understanding how local potentials affect system eigenmodes is crucial for experimental studies of nontrivial bulk topology. Recent studies have discovered many exotic and highly non-trivial topological states in non-Hermitian systems. As such, it would ... More
Path Integral Molecular Dynamics for BosonsMay 22 2019Trapped Bosons exhibit fundamental physical phenomena and are potentially useful for quantum technologies. We present a method for simulating Bosons using path integral molecular dynamics. A main challenge for simulations is including all permutations ... More
Critical transport and vortex dynamics in a thin atomic Josephson junctionMay 21 2019We study the onset of dissipation in an atomic Josephson junction between Fermi superfluids in the molecular Bose-Einstein condensation limit of strong attraction. Our simulations identify the critical population imbalance and the maximum Josephson current ... More
Thermally assisted Thouless pumping in the Rice-Mele modelMay 21 2019We investigate the effect of dissipation from a thermal environment on topological pumping in the Rice-Mele model. We report that dissipation can improve the robustness of pumping quantization in a regime of finite driving frequencies. Specifically, in ... More
A generalized phase space approach for solving quantum spin dynamicsMay 21 2019Numerical techniques to efficiently model out-of-equilibrium dynamics in interacting quantum many-body systems are key for advancing our capability to harness and understand complex quantum matter. Here we propose a new numerical approach which we refer ... More
Quantum quench and non-equilibrium dynamics in lattice-confined spinor condensatesMay 21 2019We present an experimental study on non-equilibrium dynamics of a spinor condensate after it is quenched across a superfluid to Mott insulator (MI) phase transition in cubic lattices. Intricate dynamics consisting of spin-mixing oscillations at multiple ... More
Slow quantum thermalization and many-body revivals from mixed phase spaceMay 21 2019Describing the way strongly interacting quantum systems approach thermal equilibrium remains an important open problem. Recent works discovered systems in which thermalization rates may depend very sensitively on the initial conditions, via a mechanism ... More
Quantum Rydberg Central Spin ModelMay 21 2019We consider dynamics of a Rydberg impurity in a cloud of ultracold bosonic atoms in which the Rydberg electron can undergo spin-changing collisions with surrounding atoms. This system realizes a new type of the quantum impurity problem that compounds ... More
Spontaneous formation of polar superfluid droplets in a p-wave interacting Bose gasMay 21 2019We study the quantum fluctuations in the condensates of a mixture of bosonic atoms and molecules with interspecies p-wave interaction. Our analysis shows that the quantum phase of coexisting atomic and molecular condensates is unstable at the mean-field ... More
Effective Spin-2 Quasi-particles at Linear Dispersive Five-fold Degenerate Points with Tunable Topological Chern NumbersMay 21 2019In this work, which is based on spin-2 vectors and traceless spin-2 tensors, an effective Hamiltonian is constructed with a linearly dispersive five-fold degenerate point with spin-2 vector-momentum couplings. For the model without spin-2 vector-tensor ... More
Moire Localization in Two Dimensional Quasi-Periodic SystemsMay 20 2019We discuss a two-dimensional system under the perturbation of a Moire potential, which takes the same geometry and lattice constant as the underlying lattices but mismatches up to relative rotation. Such a self-dual model belongs to the orthogonal class ... More
Controlling the dipole blockade and ionization rate of Rydberg atoms in strong electric fieldsMay 20 2019We study a novel regime of the Rydberg excitation blockade using highly Stark-shifted, yet long-living, states of Rb atoms subject to electric fields above the classical ionization limit. Such states allow tuning the dipole-dipole interaction strength ... More
Classification of Topological Excitations in Quadratic Bosonic SystemsMay 20 2019We investigate the classification of topological excitations in quadratic bosonic systems with an excitation band gap. Time-reversal, charge-conjugation, and parity symmetries in bosonic systems are introduced to realize a ten-fold symmetry classification. ... More
Realization of $\mathcal{PT}$-symmetric and $\mathcal{PT}$-symmetry broken states in static optical lattice potentialsMay 20 2019R. Labouvie et al. [Phys. Rev. Lett. 116, 235302 (2016)] have described an experiment with a weakly interacting Bose-Einstein condensate trapped in a one-dimensional optical lattice with localized loss created by a focused electron beam. We show that ... More
Multifractality of the kicked rotor at the critical point of the Anderson transitionMay 20 2019We show that quantum wavepackets exhibit a sharp macroscopic peak as they spread in the vicinity of the critical point of the Anderson transition. The peak gives a direct access to the mutifractal properties of the wavefunctions and specifically to the ... More
Breather induced quantized superfluid vortex filaments and their characterizationMay 20 2019We study and characterize the breather-induced quantized superfluid vortex filaments which correspond to the Kuznetsov-Ma breather and super-regular breather excitations developing from localised perturbations. Such vortex filaments, emerging from an ... More
Low-Dimensional Self-Bound Quantum Rabi-Coupled Bosonic DropletsMay 19 2019We analytically calculate the leading quantum corrections of the ground-state energy of two- and one-dimensional weakly interacting Rabi-coupled Bose-Bose mixtures in the frame of the Bogoliubov approximation. We show that to repulsive intraspecies and ... More
Sub-picosecond thermalization dynamics in condensation of strongly coupled lattice plasmonsMay 18 2019Bosonic condensates offer exciting prospects for studies of non-equilibrium quantum dynamics. Understanding the dynamics is particularly challenging in the sub-picosecond timescales typical for room temperature luminous driven-dissipative condensates. ... More
Topological Phase Transition Independent of System Non-HermiticityMay 18 2019Non-Hermiticity can vary the topology of system, induce topological phase transition, and even invalidate the conventional bulk-boundary correspondence. Here, we show the introducing of non-Hermiticity without affecting the topological properties of the ... More
Thermodynamics of a one-dimensional Bose gas with repulsive contact interactionsMay 17 2019We present a thorough study of the thermodynamics of a one-dimensional repulsive Bose gas, focusing in particular on corrections beyond the Luttinger-liquid description. We compute the chemical potential, the pressure and the contact, as a function of ... More
Feynman path-integral treatment of the Bose polaron beyond the Fröhlich modelMay 17 2019An impurity immersed in a Bose-Einstein condensate is no longer accurately described by the Fr\"ohlich Hamiltonian as the coupling between the impurity and the boson bath gets stronger. We study the dominant effects of the two-phonon terms beyond the ... More
Morphological Superfluid in a Nonmagnetic Spin-2 Bose-Einstein CondensateMay 17 2019The two known mechanisms for superflow are the gradient of the U(1) phase and the spin-orbit-gauge symmetry. We find the third mechanism, namely a spatial variation of the order-parameter morphology protected by a hidden su(2) symmetry in a nonmagnetic ... More
Elastic scattering of three ultracold bosonsMay 17 2019Elastic scattering of three bosons at low energy is a fundamental problem in the many-body description of ultracold Bose gases, entering via the three-body scattering hypervolume $D$. We study this quantity for identical bosons that interact via a pairwise ... More
The one-dimensional Bose-Fermi-Hubbard model in the limit of fast fermionsMay 16 2019We discuss the ground-state phase diagram of the one-dimensional Bose-Fermi-Hubbard model (BFHM) in the limit of fast fermions based on an effective boson model. We give a detailed derivation of the effective model with long-range RKKY-type interactions, ... More
Trapping laser excitation during collisions limits the lifetime of ultracold moleculesMay 16 2019The lifetime of nonreactive ultracold bialkali gases was thought to be limited by sticky collisions that amplify three-body loss. We show that the sticking times were previously overestimated and cannot explain the observed loss. Instead, we consider ... More
A quasiclassical method for calculating the density of states of ultracold collision complexesMay 16 2019We derive a quasiclassical expression for the density of states (DOS) of an arbitrary, ultracold, N-atom collision complex, for a general potential energy surface (PES). We establish the accuracy of our quasiclassical method by comparing to exact quantum ... More