Does a distinct quasi many-body localized phase exist? A numerical study of a translationally invariant system in the thermodynamic limit

Abstract

We consider a quench in an infinite spin ladder describing a system with two species of bosons in the limit of strong interactions. If the heavy bosonic species has infinite mass the model becomes a spin chain with quenched binary disorder which shows true Anderson localization (AL) or many-body localization (MBL). For finite hopping amplitude $J^{\prime }$ of the heavy particles, on the other hand, we find an exponential polarization decay with a relaxation rate which depends monotonically on $J^{\prime }$. Furthermore, the entanglement entropy changes from a constant (AL) or logarithmic (MBL) scaling in time $t$ for $J^{\prime }=0$ to a sub-ballistic power-law, $S_{\text{ent}}\sim t^{\alpha }$ with $\alpha <1$, for finite $J^{\prime }$. We do not find a distinct regime in time where the dynamics for $J^{\prime }\ne 0$ shows the characteristics of an MBL phase. Instead, we discover a time regime with distinct dephasing and entanglement times, different both from a localized and a fully ergodic phase.

Extensive exact diagonalization data added showing that for $1/J^{\prime }<t<D/J^{\prime 2}$ (i) the qualitative behavior does not depend on the particular initial state chosen, and (ii) that the power law increase of the entanglement entropy and exponential decay of the polarization cannot be resolved for small clusters. Considering system sizes L >> vt is essential

References in corpus (15)

• Many body localization and thermalization in quantum statistical mechanics
• Direct observation of Anderson localization of matter-waves in a controlled disorder
• Many-body localization edge in the random-field Heisenberg chain
• Many body localization in Heisenberg XXZ magnet in a random field
• Localization of ultrasound in a three-dimensional elastic network
• Quench dynamics and non equilibrium phase diagram of the Bose-Hubbard model
• Absence of diffusion in an interacting system of spinless fermions on a one-dimensional disordered lattice
• Relaxation of antiferromagnetic order in spin-1/2 chains following a quantum quench
• Dynamics in many-body localized quantum systems without disorder
• Purification and many-body localization in cold atomic gases
• Many-body localization in infinite chains
• Scenario for delocalization in translation invariant systems
• Quantum quenches and many-body localization in the thermodynamic limit
• Slow Dynamics in Translation-Invariant Quantum Lattice Models
• Finite-size scaling with respect to interaction and disorder strength at the many-body localization transition

Cited by in corpus (12)

• Dynamics of strongly interacting systems: From Fock-space fragmentation to Many-Body Localization
• Probing transport and slow relaxation in the mass-imbalanced Fermi-Hubbard model
• Decay of spin-spin correlations in disordered quantum and classical spin chains
• Tunable transport in the mass-imbalanced Fermi-Hubbard model
• Density dynamics in the mass-imbalanced Hubbard chain
• Stable many-body localization under random continuous measurements in the no-click limit
• Logarithmic entanglement growth in two-dimensional disordered fermionic systems
• Many-body localization and delocalization dynamics in the thermodynamic limit
• Anomalous Diffusion, Prethermalization, and Particle Binding in an Interacting Flat Band System
• Many-Body Localization in Translational Invariant Diamond Ladders with Flat Bands
• Particle pairing causes subdiffusion of heavy particles in the imbalanced Hubbard model
• Entanglement Growth from Entangled States: A Unified Perspective on Entanglement Generation and Transport