Phase separation of a Bose-Bose mixture: impact of the trap and particle number imbalance

Abstract

We explore a few-body mixture of two bosonic species confined in quasi-one-dimensional parabolic traps of different length scales. The ground state phase diagrams in the three-dimensional parameter space spanned by the harmonic length scale ratio, inter-species coupling strength and particle number ratio are investigated. As a first case study we use the mean-field ansatz (MF) to perform a detailed analysis of the separation mechanism. It allows us to derive a simple and intuitive rule predicting which of the immiscible phases is energetically more favorable at the miscible-immiscible phase boundary. We estimate the critical coupling strength for the miscible-immiscible transition and perform a comparison to correlated many-body results obtained by means of the Multi-Layer Multi-Configuration Time Dependent Hartree method for bosonic mixtures (ML-X). At a critical ratio of the trap frequencies, determined solely by the particle number ratio, the deviations between MF and ML-X are very pronounced and can be attributed to a high degree of entanglement between the components. As a result, we evidence the breakdown of the effective one-body picture. Additionally, when many-body correlations play a substantial role, the one-body density is in general not sufficient for deciding upon the phase at hand which we demonstrate exemplarily.

16 pages, 9 figures

References in corpus (27)

• Many-Body Physics with Ultracold Gases
• A High Phase-Space-Density Gas of Polar Molecules
• Quantum liquid droplets in a mixture of Bose-Einstein condensates
• Oscillations and interactions of dark and dark-bright solitons in Bose-Einstein condensates
• Ultracold dense samples of dipolar RbCs molecules in the rovibrational and hyperfine ground state
• Creation of ultracold ${}^{87}$RbCs molecules in the rovibrational ground state
• Double species condensate with tunable interspecies interactions
• Generation of dark-bright soliton trains in superfluid-superfluid counterflow
• Dual-Species Bose-Einstein Condensate of ${}^{87}$Rb and ${}^{133}$Cs
• Observation of heteronuclear atomic Efimov resonances
• Species-specific optical lattices
• Production of a dual-species Bose-Einstein condensate of Rb and Cs atoms
• Binary Quantum Turbulence Arising from Countersuperflow Instability in Two-Component Bose-Einstein Condensates
• Engineering the Dynamics of Effective Spin-Chain Models for Strongly Interacting Atomic Gases
• Composite fermionization of 1-D Bose-Bose mixtures
• Controlling phase separation of a two-component Bose-Einstein condensate by confinement
• Quantum correlations and spatial localization in one-dimensional ultracold bosonic mixtures
• Quantum magnetism in strongly interacting one-dimensional spinor Bose systems
• Many-body quantum dynamics and induced correlations of Bose polarons
• Dynamical pattern formation during growth of a dual-species Bose-Einstein condensate
• Coherent heteronuclear spin dynamics in an ultracold spin-1 mixture
• Ground-state properties of interacting two-component Bose gases in a one-dimensional harmonic trap
• The mixing-demixing phase diagram of ultracold heteronuclear mixtures in a ring trimer
• Doping a lattice-trapped bosonic species with impurities: From ground state properties to correlated tunneling dynamics
• Spectral properties and breathing dynamics of a few-body Bose-Bose mixture in a 1D harmonic trap
• Residual entropy and critical behavior of two interacting boson species in a double well
• Interplay of phase separation and itinerant magnetism for correlated few fermions in a double-well

Cited by in corpus (11)

• Few-body Bose gases in low dimensions -- a laboratory for quantum dynamics
• Quantum mixtures of ultracold gases of neutral atoms
• Self-Pinning Transition of a Tonks-Girardeau Gas in a Bose-Einstein Condensate
• Miscibility of Binary Bose-Einstein Condensates with $p$-wave Interaction
• Entangling lattice-trapped bosons with a free impurity: impact on stationary and dynamical properties
• Structure and dynamics of binary Bose-Einstein condensates with vortex phase imprinting
• Effective approaches to the dynamical properties of two distinguishable Bose polarons
• Breathing dynamics of the Bose polaron in a species-selective harmonic trap
• Phase diagram of two-component mean-field Bose mixtures
• Collective modes of two-species Bose-Einstein condensates in a Josephson junction barrier
• Phases and dynamics of an impurity immersed in one-dimensional quantum droplets