Ergodic inclusions in many body localized systems

arXiv (Cornell University)

Abstract

We investigate the effect of ergodic inclusions in putative many-body localized systems. To this end, we consider the random field Heisenberg chain, which is many-body localized at strong disorder and we couple it to an ergodic bubble, modeled by a random matrix Hamiltonian. Recent theoretical work suggests that the ergodic bubble destabilizes the apparent localized phase at intermediate disorder strength and finite sizes. We tentatively confirm this by numerically analyzing the response of the local thermality, quantified by one-site purities, to the insertion of the bubble. For a range of intermediate disorder strengths, this response decays very slowly, or not at all, with increasing distance to the bubble. This suggests that at those disorder strengths, the system is delocalized in the thermodynamic limit. However, the numerics is unfortunately not unambiguous and we cannot definitely rule out artefacts.

Authors 3

1. Luis Colmenárez Aachen Institute for Quantum Information

   RWTH Aachen University · Forschungszentrum Jülich · Max Planck Institute for the Physics of Complex Systems

   Affiliation as printed

   Forschungszentrum Jülich

   Institute for Quantum Information, RWTH Aachen University, 52056 Aachen, Germany

   Institute for Theoretical Nanoelectronics (PGI-2), Forschungszentrum Jülich, 52428 Jülich, Germany

   Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187-Dresden, Germany

2. David J. Luitz

   University of Bonn

   Affiliation as printed

   Institute of Physics, University of Bonn, Nußallee 12, 53115 Bonn, Germany

3. Wojciech De Roeck

   KU Leuven

   Affiliation as printed

   KU Leuven, 3001 Leuven, Belgium