Investigating many-body mobility edges in isolated quantum systems

TL;DR

This paper explores the existence of many-body mobility edges in isolated quantum systems, proposing experimental methods to detect them through local observables and analyzing an interacting fermion model with long-range tunneling.

Contribution

It introduces an experimental approach to identify many-body mobility edges and demonstrates their presence in an interacting fermion model with long-range tunneling.

Findings

Many-body mobility edges are observable via local degrees of freedom.

Finite-size effects do not fully explain the mobility edges.

The model exhibits clear signatures of mobility edges with interactions.

Abstract

The existence of many-body mobility edges in closed quantum systems has been the focus of intense debate after the emergence of the description of the many-body localization phenomenon. Here we propose that this issue can be settled in experiments by investigating the time evolution of local degrees of freedom, tailored for specific energies and initial states. An interacting model of spinless fermions with exponentially long-ranged tunneling amplitudes, whose non-interacting version known to display single-particle mobility edges, is used as the starting point upon which nearest-neighbor interactions are included. We verify the manifestation of many-body mobility edges by using numerous probes, suggesting that one cannot explain their appearance as merely being a result of finite-size effects.