Trends of information backflow in disordered spin chains

¹ Instituto de Física Téorica UAM/CSIC - C/Nicolás Cabrera 13-15, Cantoblanco, 28049 Madrid, Spain
² Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China Chengdu 610051, China
³ ICFO–Institut de Ciéncies Fotóniques, The Barcelona Institute of Science and Technology - 08860 Castelldefels, Spain

Received: 21 November 2019
Accepted: 14 February 2020

Abstract

We investigate the trends of information backflow associated with the dynamics of a sub-part of a disordered spin-1/2 transverse field Heisenberg chain for different regimes of the Hamiltonian. Towards this aim, the decay profile of bipartite entanglement shared between a probe-qubit and a system-qubit (sub-part) of the chain is monitored in time. A clear shift in the trends of the decay profiles of the bipartite entanglement from monotonic in the low-disorder limit to non-monotonic in the moderately large disorder limit occurs due to strong information backflow from the environment (complementary part) to the system-qubit. A connection between environmental interruption caused by the information backflow and the disorder strength is established by examining the entanglement revival frequencies. The growth patterns of the revival frequencies in the localized phase plays an instrumental role to effectively distinguish an interacting system (many-body localized) from its non-interacting (Anderson localized) counterpart.