English

Disorder-induced two-body localised state in interacting quantum walks

Mesoscale and Nanoscale Physics 2020-02-19 v1 Disordered Systems and Neural Networks Statistical Mechanics

Abstract

We observe the onset of non-ergodicity from ballistic propagation of a two-body bound state in an interacting discrete-time quantum walk (DTQW) due to time-dependent disorder in the interaction. The effect of the disorder on the two-body state can be interpreted as Anderson-type localisation in a projected DTQW, but without saturation of entanglement entropy. We characterise the two-body localisation in terms of the rate of growth of entanglement entropy and compute the localisation length. We find indications for two distinct growth laws for the entanglement: a logarithmic law in the delocalised phase and a double logarithmic law in the localised phase. We discuss similarities with many-body localisation (MBL).

Keywords

Cite

@article{arxiv.1911.06246,
  title  = {Disorder-induced two-body localised state in interacting quantum walks},
  author = {L. A. Toikka},
  journal= {arXiv preprint arXiv:1911.06246},
  year   = {2020}
}
R2 v1 2026-06-23T12:16:09.412Z