Interaction-Induced Weakening of Localization in Few-Particle Disordered Heisenberg Chains

Abstract

We investigate real-space localization in the few-particle regime of the XXZ spin-$1/2$ chain with a random magnetic field. Our investigation focuses on the time evolution of the spatial variance of non-equilibrium densities, as resulting for a specific class of initial states, namely, pure product states of densely packed particles. Varying the strength of both particle-particle interactions and disorder, we numerically calculate the long-time evolution of the spatial variance $\sigma (t)$. For the two-particle case, the saturation of this variance yields an increased but finite localization length, with a parameter scaling different to known results for bosons. We find that this interaction-induced increase is the stronger the more particles are taken into account in the initial condition. We further find that our non-equilibrium dynamics are clearly inconsistent with normal diffusion and instead point to subdiffusive dynamics with $\sigma (t)\propto t^{1/4}$.

7 pages, 7 figures

References in corpus (17)

• Many body localization and thermalization in quantum statistical mechanics
• Anderson Transitions
• Localization of interacting fermions at high temperature
• Many-body localization edge in the random-field Heisenberg chain
• Many body localization in Heisenberg XXZ magnet in a random field
• Phenomenology of fully many-body-localized systems
• Anomalous diffusion and Griffiths effects near the many-body localization transition
• Absence of diffusion in an interacting system of spinless fermions on a one-dimensional disordered lattice
• Diffusive and subdiffusive spin transport in the ergodic phase of a many-body localizable system
• The quasi-periodic Bose-Hubbard model and localization in one-dimensional cold atomic gases
• Time-step targetting methods for real-time dynamics using DMRG
• The crossover from strong to weak chaos for nonlinear waves in disordered systems
• Spin and energy currents in integrable and nonintegrable spin-1/2 chains: A typicality approach to real-time autocorrelations
• Finite temperature transport in disordered Heisenberg chains
• Domain-wall melting as a probe of many-body localization
• Normal Transport Behavior in Finite One-Dimensional Chaotic Quantum Systems
• Drude weight fluctuations in many-body localized systems

Cited by in corpus (6)

• Spin subdiffusion in disordered Hubbard chain
• Delocalized charge carriers in strongly disordered t-J model
• Complete many-body localization in the t-J model caused by random magnetic field
• Dynamics of the one-dimensional Anderson insulator coupled to various bosonic baths
• Sudden removal of a static force in a disordered system: Induced dynamics, thermalization, and transport
• Absence of two-body delocalization transitions in the two-dimensional Anderson-Hubbard model