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Optimizing Quantum Gas Production by an Evolutionary Algorithm: We report on the application of an evolutionary algorithm (EA) to enhance performance of an ultra-cold quantum gas experiment. The production of a $^{87}$Rubidium Bose-Einstein condensate (BEC) can be divided into fundamental cooling steps, specifically ma...
cond-mat_quant-gas
Signatures of non-trivial pairing in the quantum walk of two-component bosons: Nearest neighbour bosons possessing only onsite interactions do not form onsite bound pairs in their quantum walk due to fermionization. We obtain signatures of non-trivial onsite pairing in the quantum walk of strongly interacting two com...
cond-mat_quant-gas
Gas-to-soliton transition of attractive bosons on a spherical surface: We investigate the ground state properties of $N$ bosons with attractive zero-range interactions characterized by the scattering length $a>0$ and confined to the surface of a sphere of radius $R$. We present the analytic solution of the problem for ...
cond-mat_quant-gas
Two-dimensional imbalanced Fermi gas in antiparallel magnetic fields: We study a two-dimensional Fermi gas with an attractive interaction subjected to synthetic magnetic fields, which are assumed to be mutually antiparallel for two different spin components with population imbalance. By employing the mean-field approxi...
cond-mat_quant-gas
Quantum many-body effects on Rydberg excitons in cuprous oxide: We investigate quantum many-body effects on Rydberg excitons in cuprous oxide induced by the surrounding electron-hole plasma. Line shifts and widths are calculated by full diagonalisation of the plasma Hamiltonian and compared to results in first order pe...
cond-mat_quant-gas
Condensate fraction and critical temperature of interacting Bose gas in anharmonic trap: By using a correlated many body method and using the realistic van der Waals potential we study several statistical measures like the specific heat, transition temperature and the condensate fraction of the interacting Bose gas t...
cond-mat_quant-gas
Vortex stream generation and enhanced propagation in a polariton superfluid: In this work, we implement a new experimental configuration which exploits the specific properties of the optical bistability exhibited by the polariton system and we demonstrate the generation of a superfluid turbulent flow in the wake of a...
cond-mat_quant-gas
Interaction effects on dynamic correlations in non-condensed Bose gases: We consider dynamic, i.e., frequency-dependent, correlations in non-condensed ultracold atomic Bose gases. In particular, we consider the single-particle correlation function and its power spectrum. We compute this power spectrum for a one-compone...
cond-mat_quant-gas
Ground state phase diagram of the repulsive SU(3) Hubbard model in Gutzwiller approximation: We perform a variational Gutzwiller calculation to study the ground state of the repulsive SU(3) Hubbard model on the Bethe lattice with infinite coordination number. We construct a ground-state phase diagram focusing on phas...
cond-mat_quant-gas
Observation of Floquet band topology change in driven ultracold Fermi gases: Periodic driving of a quantum system can significantly alter its energy bands and even change the band topology, opening a completely new avenue for engineering novel quantum matter. Although important progress has been made recently in meas...
cond-mat_quant-gas
Apparent low-energy scale invariance in two-dimensional Fermi gases: Recent experiments on a $\2d$ Fermi gas find an undamped breathing mode at twice the trap frequency over a wide range of parameters. To understand this seemingly scale-invariant behavior in a system with a scale, we derive two exact results valid acro...
cond-mat_quant-gas
Quantum quenches in the anisotropic spin-1/2 Heisenberg chain: different approaches to many-body dynamics far from equilibrium: Recent experimental achievements in controlling ultracold gases in optical lattices open a new perspective on quantum many-body physics. In these experimental setups it is possible to study ...
cond-mat_quant-gas
Bosonic Josephson effect in the Fano-Anderson model: We investigate the coherent dynamics of a non-interacting Bose-Einstein condensate in a system consisting of two bosonic reservoirs coupled via a spatially localized mode. We describe this system by a two-terminal Fano-Anderson model and investigate analytically the ...
cond-mat_quant-gas
Number squeezed and fragmented states of strongly interacting bosons in a double well: We present a systematic study of the phenomena of number squeezing and fragmentation for a repulsive Bose-Einstein condensate (BEC) in a three dimensional double well potential over a range of interaction strengths and barrier heig...
cond-mat_quant-gas
Losses in interacting quantum gases: ultra-violet divergence and its regularization: We investigate the effect of losses on an interacting quantum gas. We show that, for gases in dimension higher than one, assuming together a vanishing correlation time of the reservoir where dissipation occurs, and contact interactio...
cond-mat_quant-gas
Low-lying energy levels of a one-dimensional weakly interacting Bose gas under zero boundary conditions: We diagonalize the second-quantized Hamiltonian of a one-dimensional Bose gas with a nonpoint repulsive interatomic potential and zero boundary conditions. At weak coupling the solutions for the ground-state energ...
cond-mat_quant-gas
Spatiotemporal scaling of two-dimensional nonequilibrium exciton-polariton systems with weak interactions: We perform a numerical study on the two-dimensional nonequilibrium exciton-polariton systems driven by incoherent pumping based on the stochastic generalized Gross-Pitaevskii equation. We calculate the density f...
cond-mat_quant-gas
Formation of nonlinear X-waves in condensed matter systems: X-waves are an example of a localized wave packet solution of the homogeneous wave equation, and can potentially arise in any area of physics relating to wave phenomena, such as acoustics, electromagnetism, or quantum mechanics. They have been predicted in con...
cond-mat_quant-gas
Early Stage of Superradiance from Bose-Einstein Condensates: We investigate the dynamics of matter and optical waves at the early stage of superradiant Rayleigh scattering from Bose-Einstein Condensates. Our analysis is within a spatially dependent quantum model which is capable of providing analytic solutions for the ...
cond-mat_quant-gas
Numerical analysis of spin-orbit coupled one dimensional Fermi gas in the magnetic field: We use the density matrix renormalization group method(DMRG) and the infinite time evolved block decimation method(iTEBD) to investigate the ground states of the spin-orbit coupled Fermi gas in a one dimensional optical lattice ...
cond-mat_quant-gas
Spin dynamics and domain formation of a spinor Bose-Einstein condensate in an optical cavity: We consider a ferromagnetic spin-1 Bose-Einstein condensate (BEC) dispersively coupled to a unidirectional ring cavity. We show that the ability of a cavity to modify, in a highly nonlinear fashion, matter-wave phase shifts ...
cond-mat_quant-gas
Dynamical response of ultracold interacting fermion-boson mixtures: We analyze the dynamical response of a ultracold binary gas mixture in presence of strong boson-fermion couplings. Mapping the problem onto that of the optical response of a metal/semiconductor electronic degrees of freedom to electromagnetic perturbat...
cond-mat_quant-gas
Spontaneous symmetry breaking in rotating condensates of ultracold atoms: We describe an equilibrium state of a rotating trapped atomic condensate, which is characterized by a non-zero internal circulation and spontaneous breaking of the rotational O(2) symmetry with all three major semiaxes of the condensate having di...
cond-mat_quant-gas
Expansion of the strongly interacting superfluid Fermi gas: symmetries and self-similar regimes: We consider an expansion of the strongly interacting superfluid Fermi gas in a vacuum, assuming absence of the trapping potential, in the so-called unitary regime (see, for instance, \cite{pitaevskii2008superfluid}) when ...
cond-mat_quant-gas
Superglass formation in an atomic BEC with competing long-range interactions: The complex dynamical phases of quantum systems are dictated by atomic interactions that usually evoke an emergent periodic order. Here, we study a quantum many-body system with two competing and substantially different long-range interacti...
cond-mat_quant-gas
Universality in rotating strongly interacting gases: We analytically determine the properties of two interacting particles in a harmonic trap subject to a rotation or a uniform synthetic magnetic field, where the spherical symmetry of the relative Hamiltonian is preserved. Thermodynamic quantities such as the entropy a...
cond-mat_quant-gas
Transport, atom blockade and output coupling in a Tonks-Girardeau gas: Recent experiments have demonstrated how quantum-mechanical impurities can be created within strongly correlated quantum gases and used to probe the coherence properties of these systems [S. Palzer, C. Zipkes, C. Sias, and M. K\"ohl, Phys. Rev. Lett...
cond-mat_quant-gas
Magnetic lattices for ultracold atoms and degenerate quantum gases: We review recent developments in the use of magnetic lattices as a complementary tool to optical lattices for trapping periodic arrays of ultracold atoms and degenerate quantum gases. Recent advances include the realisation of Bose-Einstein condensatio...
cond-mat_quant-gas
Deformation of a quantum many-particle system by a rotating impurity: During the last 70 years, the quantum theory of angular momentum has been successfully applied to describing the properties of nuclei, atoms, and molecules, their interactions with each other as well as with external fields. Due to the properties of ...
cond-mat_quant-gas
Multidimensional hybrid Bose-Einstein condensates stabilized by lower-dimensional spin-orbit coupling: We show that attractive spinor Bose-Einstein condensates under the action of spin-orbit coupling (SOC) and Zeeman splitting form self-sustained stable two- and three-dimensional (2D and 3D) states in free space, eve...
cond-mat_quant-gas
Few-boson tunneling in a double well with spatially modulated interaction: We study few-boson tunneling in a one-dimensional double well with a spatially modulated interaction. The dynamics changes from Rabi oscillations in the non-interacting case to a highly suppressed tunneling for intermediate coupling strengths ...
cond-mat_quant-gas
Patterned Supersolids in Dipolar Bose Systems: We study by means of first principle Quantum Monte Carlo simulations the ground state phase diagram of a system of dipolar bosons with aligned dipole moments, and with the inclusion of a two-body repulsive potential of varying range. The system is shown to display a supers...
cond-mat_quant-gas
A pathway to ultracold bosonic $^{23}\textrm{Na}^{39}\textrm{K}$ ground state molecules: We spectroscopically investigate a pathway for the conversion of $^{23}\textrm{Na}^{39}\textrm{K}$ Feshbach molecules into rovibronic ground state molecules via STImulated Raman Adiabatic Passage (STIRAP). Using photoassociation ...
cond-mat_quant-gas
Superfluidity breakdown of periodic matter waves in quasi one-dimensional annular traps via resonant scattering with moving defects: We investigate, both analytically and numerically, the quasi-superfluidity properties of periodic Bose-Einstein condensates (BECs) in a quasi-one-dimensional (1D) ring with optical latt...
cond-mat_quant-gas
Sub-micron period lattice structures of magnetic microtraps for ultracold atoms on an atom chip: We report on the design, fabrication and characterization of magnetic nanostructures to create a lattice of magnetic traps with sub--micron period for trapping ultracold atoms. These magnetic nanostructures were fabricate...
cond-mat_quant-gas
Critical velocity in resonantly driven polariton superfluids: We study the necessary condition under which a resonantly driven exciton polariton superfluid flowing against an obstacle can generate turbulence. The value of the critical velocity is well estimated by the transition from elliptic to hyperbolic of an operat...
cond-mat_quant-gas
Efficiently Extracting Multi-Point Correlations of a Floquet Thermalized System: Nonequilibrium dynamics of many-body systems is challenging for classical computing, providing opportunities for demonstrating practical quantum computational advantage with analogue quantum simulators. It is proposed to be classically i...
cond-mat_quant-gas
Snake instability of dark solitons across the BEC-BCS crossover: an effective field theory perspective: In the present article the snake instability mechanism for dark solitons in superfluid Fermi gases is studied in the context of a recently developed effective field theory [Eur. Phys. J. B 88, 122 (2015)]. This the...
cond-mat_quant-gas
Inhomogeneities and impurities in a dense one-dimensional Rydberg lattice gas: We consider a dense one-dimensional laser-driven Rydberg lattice gas with perfect nearest-neighbor blockade. The ground state of this system can be found analytically in certain parameter regimes even when the applied fields are inhomogene...
cond-mat_quant-gas
Topologically protected edge gap solitons of interacting Bosons in one-dimensional superlattices: We comprehensively investigate the nontrivial states of interacting Bose system in one-dimensional optical superlattices under the open boundary condition. Our results show that there exists a kind of stable localized st...
cond-mat_quant-gas
Fulde-Ferrell Superfluids without Spin Imbalance in Driven Optical Lattices: Spin-imbalanced ultracold Fermi gases have been widely studied recently as a platform for exploring the long-sought Fulde-Ferrell-Larkin-Ovchinnikov superfluid phases, but so far conclusive evidence has not been found. Here we propose to rea...
cond-mat_quant-gas
Composite structure of vortices in two-component Bose-Einstein condensate: In contrast to one-component Bose-Einstein condensate case, the vortices in two-component condensate can have various complicated structures. The vortices in a space-homogeneous Bose-Einstein condensate have been studied in this paper. It is s...
cond-mat_quant-gas
Spatial pattern formation and polarization dynamics of a nonequilibrium spinor polariton condensate: Quasiparticles in semiconductors -- such as microcavity polaritons -- can form condensates in which the steady-state density profile is set by the balance of pumping and decay. By taking account of the polarization de...
cond-mat_quant-gas
Controlling spontaneous-emission noise in measurement-based feedback cooling of a Bose-Einstein Condensate: Off-resonant optical imaging is the most popular method for continuous monitoring of a Bose-Einstein condensate (BEC). However, the disturbance caused by scattered photons places a serious limitation on the lif...
cond-mat_quant-gas
Association of Efimov trimers from a three-atom continuum: We develop an experimental technique for rf-association of Efimov trimers from three-atoms continuum. We apply it to probe the lowest accessible Efimov energy level in bosonic lithium in the region where strong deviations from the universal behavior are expecte...
cond-mat_quant-gas
Universal many-body response of heavy impurities coupled to a Fermi sea: In this work we discuss the dynamical response of heavy quantum impurities immersed in a Fermi gas at zero and at finite temperature. Studying both the frequency and the time domain allows one to identify interaction regimes that are characterized...
cond-mat_quant-gas
Self-induced entanglement resonance in a disordered Bose-Fermi mixture: Different regimes of entanglement growth under measurement have been demonstrated for quantum many-body systems, with an entangling phase for low measurement rates and a disentangling phase for high rates (quantum Zeno effect). Here we study entang...
cond-mat_quant-gas
Dissipative topological superconductors in number-conserving systems: We discuss the dissipative preparation of p-wave superconductors in number-conserving one-dimensional fermionic systems. We focus on two setups: the first one entails a single wire coupled to a bath, whereas in the second one the environment is conne...
cond-mat_quant-gas
Optical-plug-assisted spin vortex in a $^{87}$Rb dipolar spinor Bose-Einstein condensate: Generating a spin vortex in a $^{87}$Rb dipolar spinor Bose-Einstein condensate in a controllable way is still experimentally challenging. We propose an experimentally easy and tunable way to produce spin vortex by varying the p...
cond-mat_quant-gas
Connecting Topological Anderson and Mott Insulators in Disordered Interacting Fermionic Systems: The topological Anderson and Mott insulators are two phases that have so far been separately and widely explored beyond topological band insulators. Here we combine the two seemingly different topological phases into a sy...
cond-mat_quant-gas
Position- and momentum-space two-body correlations in a weakly interacting trapped condensate: We investigate the position- and momentum-space two--body correlations in a weakly interacting, harmonically trapped atomic Bose-Einstein condensed gas at low temperatures. The two-body correlations are computed within the ...
cond-mat_quant-gas
Phase Winding a Two-Component BEC in an Elongated Trap: Experimental Observation of Moving Magnetic Orders and Dark-bright Solitons: We experimentally investigate the phase winding dynamics of a harmonically trapped two-component BEC subject to microwave induced Rabi oscillations between two pseudospin components. Wh...
cond-mat_quant-gas
Experimental Methods for Generating Two-Dimensional Quantum Turbulence in Bose-Einstein Condensates: Bose-Einstein condensates of dilute gases are well-suited for investigations of vortex dynamics and turbulence in quantum fluids, yet there has been little experimental research into the approaches that may be most pr...
cond-mat_quant-gas
Mesoscopic quantum superpositions in bimodal Bose-Einstein condensates: decoherence and strategies to counteract it: We study theoretically the interaction-induced generation of mesoscopic coherent spin state superpositions (small cat states) from an initial coherent spin state in bimodal Bose-Einstein condensates an...
cond-mat_quant-gas
Universal contact and collective excitations of a strongly interacting Fermi gas: We study the relationship between Tan's contact parameter and the macroscopic dynamic properties of an ultracold trapped gas, such as the frequencies of the collective oscillations and the propagation of sound in one-dimensional (1D) co...
cond-mat_quant-gas
Detecting quadrupole interactions in ultracold Fermi gases: We propose to detect quadrupole interactions of neutral ultra-cold atoms via their induced mean-field shift. We consider a Mott insulator state of spin-polarized atoms in a two-dimensional optical square lattice. The quadrupole moments of the atoms are aligned...
cond-mat_quant-gas
Superfluidity of a Raman spin-orbit-coupled Bose gas at finite temperature: We investigate the superfluidity of a three-dimensional weakly interacting Bose gas with a one-dimensional Raman-type spin-orbit coupling at both zero and finite temperatures. Using the imaginary-time Green's function within the Bogoliubov ap...
cond-mat_quant-gas
Sudden and slow quenches into the antiferromagnetic phase of ultracold fermions: We propose a method to reach the antiferromagnetic state of two-dimensional Fermi gases trapped in optical lattices: Independent subsystems are prepared in suitable initial states and then connected by a sudden or slow quench of the tunn...
cond-mat_quant-gas
Itinerant ferromagnetism of two-dimensional repulsive fermions with Rabi coupling: We study a two-dimensional fermionic cloud of repulsive alkali-metal atoms characterized by two hyperfine states which are Rabi coupled. Within a variational Hartree-Fock scheme, we calculate analytically the ground-state energy of the...
cond-mat_quant-gas
Three-body repulsive forces among identical bosons in one dimension: I consider non-relativistic bosons interacting via pairwise potentials with infinite scattering length and supporting no two-body bound states. To lowest order in effective field theory, these conditions lead to non-interacting bosons, since the coupl...
cond-mat_quant-gas
Measuring entropy and mutual information in the two-dimensional Hubbard model: We measure pressure and entropy of ultracold fermionic atoms in an optical lattice for a range of interaction strengths, temperatures and fillings. Our measurements demonstrate that, for low enough temperatures, entropy-rich regions form l...
cond-mat_quant-gas
Synthetic Dimensions for Cold Atoms from Shaking a Harmonic Trap: We introduce a simple scheme to implement synthetic dimensions in ultracold atomic gases, which only requires two basic and ubiquitous ingredients: the harmonic trap, which confines the atoms, combined with a periodic shaking. In our approach, standard h...
cond-mat_quant-gas
Compressibility and entropy of cold fermions in one dimensional optical lattices: We calculate several thermodynamic quantities for repulsively interacting one-dimensional fermions.We solve the Hubbard model at both zero and finite temperatures using the Bethe-ansatz method. For arbitrary values of the chemical poten...
cond-mat_quant-gas
Interacting bosonic flux ladders with a synthetic dimension: Ground-state phases and quantum quench dynamics: Flux ladders constitute the minimal setup enabling a systematic understanding of the rich physics of interacting particles subjected simultaneously to strong magnetic fields and a lattice potential. In this p...
cond-mat_quant-gas
Reliable equation of state for composite bosons in the 2D BCS-BEC crossover: We briefly discuss recent experiments on the BCS-BEC crossover with ultracold alkali-metal atoms both in three-dimensional configurations and two-dimensional ones. Then we analyze the quantum-field-theory formalism used to describe an attrac...
cond-mat_quant-gas
Loss-induced phase separation and pairing for 3-species atomic lattice fermions: We study the physics of a three-component Fermi gas in an optical lattice, in the presence of a strong three-body constraint arising due to three-body loss. Using analytical and numerical techniques, we show that an atomic color superflu...
cond-mat_quant-gas
A mobile ion in a Fermi sea: The remarkable single particle control of individual ions combined with the versatility of ultracold atomic gases makes hybrid ion-atom system an exciting new platform for quantum simulation of few- and many-body quantum physics. Here, we study theoretically the properties of a mobile ion i...
cond-mat_quant-gas
Quantum Chaos in Ultracold Collisions of Erbium: Atomic and molecular samples reduced to temperatures below 1 microkelvin, yet still in the gas phase, afford unprecedented energy resolution in probing and manipulating how their constituent particles interact with one another. For simple atoms, such as alkalis, scatteri...
cond-mat_quant-gas
Different models of gravitating Dirac fermions in optical lattices: In this paper I construct the naive lattice Dirac Hamiltonian describing the propagation of fermions in a generic 2D optical metric for different lattice and flux-lattice geometries. First, I apply a top-down constructive approach that we first propose...
cond-mat_quant-gas
Realizing Hopf Insulators in Dipolar Spin Systems: The Hopf insulator is a weak topological insulator characterized by an insulating bulk with conducting edge states protected by an integer-valued linking number invariant. The state exists in three-dimensional two-band models. We demonstrate that the Hopf insulator can...
cond-mat_quant-gas
State selective cooling of $\mathrm{SU}(N)$ Fermi-gases: We investigate a species selective cooling process of a trapped $\mathrm{SU}(N)$ Fermi gas using entropy redistribution during adiabatic loading of an optical lattice. Using high-temperature expansion of the Hubbard model, we show that when a subset $N_A < N$ of ...
cond-mat_quant-gas
Anomalous supersolidity in a weakly interacting dipolar Bose mixture on a square lattice: We calculate the mean-field phase diagram of a zero-temperature, binary Bose mixture on a square optical lattice, where one species possesses a non-negligible dipole moment. Remarkably, this system exhibits supersolidity for ano...
cond-mat_quant-gas
Supersolid phases of lattice dipoles tilted in three-dimensions: By means of quantum Monte Carlo simulations we study phase diagrams of dipolar bosons in a square optical lattice. The dipoles in the system are parallel to each other and their orientation can be fixed in any direction of the three-dimensional space. Sta...
cond-mat_quant-gas
Realizing quantum Ising models in tunable two-dimensional arrays of single Rydberg atoms: Spin models are the prime example of simplified manybody Hamiltonians used to model complex, real-world strongly correlated materials. However, despite their simplified character, their dynamics often cannot be simulated exactly...
cond-mat_quant-gas
Fate of the Mollow triplet in strongly-coupled atomic arrays: Subwavelength arrays of quantum emitters have emerged as an interesting platform displaying prominent collective effects. Here we study such arrays under coherent driving, realizing an open quantum many-body problem in a strongly non-linear regime. We show t...
cond-mat_quant-gas
Spatially Modulated Interaction Induced Bound States and Scattering Resonances: We study the two-body problem with a spatially modulated interaction potential using a two-channel model, in which the inter-channel coupling is provided by an optical standing wave and its strength modulates periodically in space. As the...
cond-mat_quant-gas
Quantum-geometric perspective on spin-orbit-coupled Bose superfluids: We employ the Bogoliubov approximation to study how the quantum geometry of the helicity states affects the superfluid properties of a spin-orbit-coupled Bose gas in continuum. In particular we derive the low-energy Bogoliubov spectrum for a plane-wa...
cond-mat_quant-gas
Properties of the Superfluid in the Disordered Bose-Hubbard Model: We investigate the properties of the superfluid phase in the three-dimensional disordered Bose-Hubbard model using Quantum Monte-Carlo simulations. The phase diagram is generated using Gaussian disorder on the on-site potential. Comparisons with box and...
cond-mat_quant-gas
Diffusion Monte Carlo methods for Spin-Orbit-Coupled ultracold Bose gases: We present two Diffusion Monte Carlo (DMC) algorithms for systems of ultracold quantum gases featuring synthetic spin-orbit interactions. The first one is a discrete spin generalization of the T- moves spin-orbit DMC, which provides an upper b...
cond-mat_quant-gas
Many-body approach to low-lying collective excitations in a BEC approaching collapse: An approximate many-body theory incorporating two-body correlations has been employed to calculate low-lying collective multipole frequencies in a Bose-Einstein condensate containing $A$ bosons, for different values of the interacti...
cond-mat_quant-gas
Multicriticality, Metastability, and Roton Feature in Bose-Einstein Condensates with Three-Dimensional Spin-Orbit Coupling: We theoretically study homogeneously trapped atomic Bose-Einstein condensates where all three momentum components couple to a pseudo-spin-$1/2$ degree of freedom. Tuning the anisotropies of spin...
cond-mat_quant-gas
Instability of superfluid Fermi gases induced by a roton-like density mode in optical lattices: We study the stability of superfluid Fermi gases in deep optical lattices in the BCS--Bose-Einstein condensation (BEC) crossover at zero temperature. Within the tight-binding attractive Hubbard model, we calculate the spec...
cond-mat_quant-gas
Local correlations in the attractive 1D Bose gas: from Bethe ansatz to the Gross-Pitaevskii equation: We consider the ground-state properties of an extended one-dimensional Bose gas with pointwise attractive interactions. We take the limit where the interaction strength goes to zero as the system size increases at fi...
cond-mat_quant-gas
Degenerate approach to the mean field Bose- Hubbard Hamiltonian: A degenerate variant of mean field perturbation theory for the on-site Bose-Hubbard Hamiltonian is presented. We split the perturbation into two terms and perform exact diagonalization in the two-dimensional subspace corresponding to the degenerate states...
cond-mat_quant-gas
A long-lived Higgs mode in a two-dimensional confined Fermi gas: The Higgs mode corresponds to the collective motion of particles due to the vibrations of an invisible field. It plays a fundamental role for our understanding of both low and high energy physics, giving elementary particles their mass and leading to coll...
cond-mat_quant-gas
Modulational instability and soliton generation in chiral Bose-Einstein condensates with zero-energy nonlinearity: By means of analytical and numerical methods, we address the modulational instability (MI) in chiral condensates governed by the Gross-Pitaevskiiequation including the current nonlinearity. The analysis ...
cond-mat_quant-gas
Thermodynamics of a Bose gas near the superfluid--Mott-insulator transition: We study the thermodynamics near the generic (density-driven) superfluid--Mott-insulator transition in the three-dimensional Bose-Hubbard model using the nonperturbative renormalization-group approach. At low energy the physics is controlled...
cond-mat_quant-gas
Criticality-enhanced quantum sensing in ferromagnetic Bose-Einstein condensates: role of readout measurement and detection noise: We theoretically investigate estimation of the control parameter in a ferromagnetic Bose-Einstein condensate near second order quantum phase transitions. We quantify sensitivity by quantum...
cond-mat_quant-gas
Intermediate super-exponential localization with Aubry-André chains: We demonstrate the existence of an intermediate super-exponential localization regime for eigenstates of the Aubry-Andr\'e chain. In this regime, the eigenstates localize factorially similarly to the eigenstates of the Wannier-Stark ladder. The super-...
cond-mat_quant-gas
Theoretical Prediction of Non-Hermitian Skin Effect in Ultracold Atom Systems: Non-Hermitian skin effect, which refers to the phenomenon that an extensive number of eigenstates are localized at the boundary, has been widely studied in lattice models and experimentally observed in several classical systems. In this wo...
cond-mat_quant-gas
Signatures of non-trivial pairing in the quantum walk of two-component bosons: Nearest neighbour bosons possessing only onsite interactions do not form onsite bound pairs in their quantum walk due to fermionization. We obtain signatures of non-trivial onsite pairing in the quantum walk of strongly interacting two com...
cond-mat_quant-gas
Virial coefficients for Bose and Fermi trapped gases beyond the unitary limit: an S-Matrix approach: We study the virial expansion for three-dimensional Bose and Fermi gases at finite temperature using an approximation that only considers two-body processes and is valid for high temperatures and low densities. The fi...
cond-mat_quant-gas
The Higgs mode in a superfluid of Dirac fermions: We study the Higgs amplitude mode in the s-wave superfluid state on the honeycomb lattice inspired by recent cold atom experiments. We consider the attractive Hubbard model and focus on the vicinity of a quantum phase transition between semi-metal and superfluid phases....
cond-mat_quant-gas
Revealing Hidden Antiferromagnetic Correlations in Doped Hubbard Chains via String Correlators: Topological phases, like the celebrated Haldane phase in spin-1 chains, defy characterization through local order parameters. Instead, non-local string order parameters can be employed to reveal their hidden order. Similar...
cond-mat_quant-gas
Thermodynamic signatures for topological phase transitions to Majorana and Weyl superfluids in ultracold Fermi gases: We discuss the thermodynamic signatures for the topological phase transitions into Majorana and Weyl superfluid phases in ultracold Fermi gases in two and three dimensions in the presence of Rashba sp...
cond-mat_quant-gas
Majorana edge-modes in a spinful particle conserving model: We show the presence of Majorana edge modes in an interacting fermionic ladder with spin in a number conserved setting. The interchain single particle hopping is suppressed and only a pair hopping is present between the different chains of the ladder. Addition...
cond-mat_quant-gas
Long-range transverse Ising model built with dipolar condensates in two-well arrays: Dipolar Bose-Einstein condensates in an array of double-well potentials realize an effective transverse Ising model with peculiar inter-layer interactions, that may result under proper conditions in an anomalous first-order ferromagn...
cond-mat_quant-gas
Interactions and dynamics of one-dimensional droplets, bubbles and kinks: We explore the dynamics and interactions of multiple bright droplets and bubbles, as well as the interactions of kinks with droplets and with antikinks, in the extended one-dimensional Gross-Pitaevskii model including the Lee-Huang-Yang correctio...
cond-mat_quant-gas
Above-Barrier Reflection of Cold Atoms by Resonant Laser Light within the Gross-Pitaevskii Approximation: Above-barrier reflection of cold alkali atoms by resonant laser light was considered analytically within the Gross-Pitaevskii approximation. Correction for the reflection coefficient because of a weak nonlinearit...
cond-mat_quant-gas
A proof to Biswas-Mitra-Bhattacharyya conjecture for ideal quantum gas trapped under generic power law potential $U=\sum_{i=1} ^d c_i |\frac {x_i}{a_i}|^{n_i}$ in $d$ dimension: The well known relation for ideal classical gas $\Delta \epsilon^2=kT^2 C_V$ which does not remain valid for quantum system is revisited. ...
cond-mat_quant-gas