Density dynamics in the mass-imbalanced Hubbard chain

Abstract

We consider two mutually interacting fermionic particle species on a one-dimensional lattice and study how the mass ratio $\eta$ between the two species affects the (equilibration) dynamics of the particles. Focussing on the regime of strong interactions and high temperatures, two well-studied points of reference are given by (i) the case of equal masses $\eta =1$, i.e., the standard Fermi-Hubbard chain, where initial non-equilibrium density distributions are known to decay, and (ii) the case of one particle species being infinitely heavy, $\eta =0$, leading to a localization of the lighter particles in an effective disorder potential. Given these two opposing cases, the dynamics in the case of intermediate mass ratios $0<\eta <1$ is of particular interest. To this end, we study the real-time dynamics of pure states featuring a sharp initial non-equilibrium density profile. Relying on the concept of dynamical quantum typicality, the resulting non-equilibrium dynamics can be related to equilibrium correlation functions. Summarizing our main results, we observe that diffusive transport occurs for moderate values of the mass imbalance, and manifests itself in a Gaussian spreading of real-space density profiles and an exponential decay of density modes in momentum space. For stronger imbalances, we provide evidence that transport becomes anomalous on intermediate time scales and, in particular, our results are consistent with the absence of strict localization in the long-time limit for any $\eta >0$. Based on our numerical analysis, we provide an estimate for the "lifetime" of the effective localization as a function of $\eta$.

arXiv comment12 pages, 17 figures

References in corpus (71)

• Chaos and Quantum Thermalization
• Thermalization and its mechanism for generic isolated quantum systems
• Nonequilibrium dynamics of closed interacting quantum systems
• Many body localization and thermalization in quantum statistical mechanics
• From Quantum Chaos and Eigenstate Thermalization to Statistical Mechanics and Thermodynamics
• Many-body localization, thermalization, and entanglement
• Anderson localization of a non-interacting Bose-Einstein condensate
• Observation of many-body localization of interacting fermions in a quasi-random optical lattice
• Direct observation of Anderson localization of matter-waves in a controlled disorder
• Quantum many-body systems out of equilibrium
• The Kernel Polynomial Method
• The foundations of statistical mechanics from entanglement: Individual states vs. averages
• Equilibration, thermalisation, and the emergence of statistical mechanics in closed quantum systems
• Many-body localization in a quantum simulator with programmable random disorder
• Canonical Typicality
• Universal dynamics and renormalization in many body localized systems
• Quantum Chaos and Thermalization in Isolated Systems of Interacting Particles
• Diffusive and subdiffusive spin transport in the ergodic phase of a many-body localizable system
• Signatures of Many-Body Localization in a Controlled Open Quantum System
• Typicality for Generalized Microcanonical Ensembles
• Minimally entangled typical quantum states at finite temperature
• Disorder-Free Localization
• Canonical Thermal Pure Quantum State
• Thermal Pure Quantum States at Finite Temperature
• Localization and Glassy Dynamics Of Many-Body Quantum Systems
• Many-body localization dynamics from gauge invariance
• Super-diffusion in one-dimensional quantum lattice models
• Dynamical typicality of quantum expectation values
• Pushing the limits of the eigenstate thermalization hypothesis towards mesoscopic quantum systems
• An efficient scheme for numerical simulations of the spin-bath decoherence
• Quasi Many-body Localization in Translation Invariant Systems
• Dynamics in many-body localized quantum systems without disorder
• Typical fast thermalization processes in closed many-body systems
• Spin-current autocorrelations from single pure-state propagation
• Quantum Disentangled Liquids
• Purification and many-body localization in cold atomic gases
• Many-body localization in disorder-free systems: the importance of finite-size constraints
• Regression relation for pure quantum states and its implications for efficient computing
• Random phase vector for calculating the trace of a large matrix
• Many-body localization in infinite chains
• Exploiting Quantum Parallelism To Simulate Quantum Random Many-Body Systems
• Asymptotic quantum many-body localization from thermal disorder
• Scenario for delocalization in translation invariant systems
• Absence of full many-body localization in the disordered Hubbard chain
• Distribution of local entropy in the Hilbert space of bi-partite quantum systems: Origin of Jaynes' principle
• Diffusive high-temperature transport in the one-dimensional Hubbard model
• Dynamics and Transport at the Threshold of Many-Body Localization
• Signatures of many-body localisation in a system without disorder and the relation to a glass transition
• Accuracy of the finite-temperature Lanczos method compared to simple typicality-based estimates
• Real-time broadening of non-equilibrium density profiles and the role of the specific initial-state realization
• Algorithm for Linear Response Functions at Finite Temperatures: Application to ESR spectrum of s=1/2 Antiferromagnet Cu benzoate
• Dynamical typicality of isolated many-body quantum systems
• Spin subdiffusion in disordered Hubbard chain
• Kinetic theory for a mobile impurity in a degenerate Tonks-Girardeau gas
• Slow Dynamics in Translation-Invariant Quantum Lattice Models
• Entanglement entropy of disordered quantum chains following a global quench
• Density dynamics from current auto-correlations at finite time- and length-scales
• Selected applications of typicality to real-time dynamics of quantum many-body systems
• Computational Methods for Simulating Quantum Computers
• Proposal for measuring the finite-temperature Drude weight of integrable systems
• Finite-temperature charge transport in the one-dimensional Hubbard model
• Combined use of translational and spin-rotational invariance for spin systems
• Conditioned stochastic particle systems and integrable quantum spin systems
• Decay of spin-spin correlations in disordered quantum and classical spin chains
• Magnetization dynamics in clean and disordered spin-1 XXZ chains
• Charge diffusion in the one-dimensional Hubbard model
• Transient fluctuation theorem in closed quantum systems
• Does a distinct quasi many-body localized phase exist? A numerical study of a translationally invariant system in the thermodynamic limit
• Energy spread and current-current correlation in quantum systems
• Testing the universality of the many-body metal-insulator transition by time evolution of a disordered one-dimensional ultracold fermionic gas
• Finite-size scaling of typicality-based estimates

Cited by in corpus (12)

• Finite-temperature transport in one-dimensional quantum lattice models
• Probing transport and slow relaxation in the mass-imbalanced Fermi-Hubbard model
• Tunable transport in the mass-imbalanced Fermi-Hubbard model
• Spin-1/2 XXZ chain coupled to two Lindblad baths: Constructing nonequilibrium steady states from equilibrium correlation functions
• Many-body localization and delocalization dynamics in the thermodynamic limit
• Two-doublon Bloch oscillations in the mass-imbalanced extended Fermi-Hubbard model
• One-dimensional Fermi polaron after a kick: two-sided singularity of the momentum distribution, Bragg reflection and other exact results
• Anomalous Diffusion, Prethermalization, and Particle Binding in an Interacting Flat Band System
• Many-Body Localization in Translational Invariant Diamond Ladders with Flat Bands
• Infinite temperature spin dynamics in the asymmetric Hatsugai-Kohmoto model
• Particle pairing causes subdiffusion of heavy particles in the imbalanced Hubbard model
• Anomalous Quantum Relaxation in the Infinite Temperature Hubbard Chain