Diffusive and subdiffusive spin transport in the ergodic phase of a many-body localizable system
Abstract
We study high temperature spin transport in a disordered Heisenberg chain in the ergodic regime. By employing a density matrix renormalization group technique for the study of the stationary states of the boundary-driven Lindblad equation we are able to study extremely large systems (400 spins). We find both a diffusive and a subdiffusive phase depending on the strength of the disorder and on the anisotropy parameter of the Heisenberg chain. Studying finite-size effects we show numerically and theoretically that a very large crossover length exists that controls the passage of a clean-system dominated dynamics to one observed in the thermodynamic limit. Such a large length scale, being larger than the sizes studied before, explains previous conflicting results. We also predict spatial profiles of magnetization in steady states of generic nondiffusive systems.
Keywords
Cite
@article{arxiv.1604.08567,
title = {Diffusive and subdiffusive spin transport in the ergodic phase of a many-body localizable system},
author = {Marko Znidaric and Antonello Scardicchio and Vipin Kerala Varma},
journal= {arXiv preprint arXiv:1604.08567},
year = {2016}
}
Comments
v2: updated phase diagram; 9 pages