Localisation and Sub-Diffusive Transport in Quantum Spin Chains With Dilute Disorder
arXiv:2208.03234 · doi:10.1103/PhysRevB.107.014207
Abstract
It is widely believed that many-body localisation in one dimension is fragile and can be easily destroyed by thermal inclusions, however there are still many open questions regarding the stability of the localised phase and under what conditions it breaks down. Here I construct models with dilute disorder, which interpolate between translationally invariant and fully random models, in order to study the breakdown of localisation. This opens up the possibility to controllably increase the density of thermal regions and examine the breakdown of localisation as this density is increased. At strong disorder, the numerical results are consistent with commonly-used diagnostics for localisation even when the concentration of thermalising regions is high. At moderate disorder, I present evidence for slow dynamics and sub-diffusive transport across a large region of the phase diagram, suggestive of a `bad metal' phase. This suggests that dilute disorder may be a useful effective model for studying Griffiths effects in many-body localisation, and perhaps also in a wider class of disordered systems.
12 pages, 11 figures
References in corpus (21)
- Localization of interacting fermions at high temperature
- Many-body localization edge in the random-field Heisenberg chain
- Phenomenology of fully many-body-localized systems
- Integrals of motion in the Many-Body localized phase
- QuSpin: a Python Package for Dynamics and Exact Diagonalisation of Quantum Many Body Systems part I: spin chains
- 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
- Typicality for Generalized Microcanonical Ensembles
- Anomalous thermalization in ergodic systems
- Ergodicity Breaking Transition in Finite Disordered Spin Chains
- Many-body localization dynamics from gauge invariance
- How a small quantum bath can thermalize long localized chains
- Can we study the many-body localisation transition?
- Quantum Griffiths effects and smeared phase transitions in metals: theory and experiment
- Entanglement spreading in a many-body localized system
- Delocalized Glassy Dynamics and Many Body Localization
- Dynamical phases in a "multifractal" Rosenzweig-Porter model
- Are many-body localized systems stable in the presence of a small bath?
- Sub-diffusive Thouless time scaling in the Anderson model on random regular graphs
- Enhancing disorder-free localization through dynamically emergent local symmetries
- Disorder-free localization with Stark gauge protection