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arXiv · 1911.06246

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

L. A. Toikka
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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).

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L. A. Toikka. 2019-11-14. Disorder-induced two-body localised state in interacting quantum walks. https://doi.org/10.1103/physrevb.101.064202

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