English

Locally quasi-stationary states in noninteracting spin chains

Strongly Correlated Electrons 2020-03-30 v3 Mathematical Physics math.MP Quantum Physics

Abstract

Locally quasi-stationary states (LQSS) were introduced as inhomogeneous generalisations of stationary states in integrable systems. Roughly speaking, LQSSs look like stationary states, but only locally. Despite their key role in hydrodynamic descriptions, an unambiguous definition of LQSSs was not given. By solving the dynamics in inhomogeneous noninteracting spin chains, we identify the set of LQSSs as a subspace that is invariant under time evolution, and we explicitly construct the latter in a generalised XY model. As a by-product, we exhibit an exact generalised hydrodynamic theory (including "quantum corrections").

Keywords

Cite

@article{arxiv.1910.01046,
  title  = {Locally quasi-stationary states in noninteracting spin chains},
  author = {Maurizio Fagotti},
  journal= {arXiv preprint arXiv:1910.01046},
  year   = {2020}
}

Comments

42 pages, 2 figures (with numerical checks and an improved analysis of inhomogeneous Hamiltonians)