Scrambling and many-body localization in the XXZ chain

The tripartite information is an observable-independent measure for scrambling and delocalization of information. Therefore, one can expect that the tripartite information is a good observable-independent indicator for distinguishing between many-body localized and delocalized regimes, which we confirm for the XXZ chain in a random field. Specifically, we find that the tripartite information signal spreads inside a light cone that grows only logarithmically in time in the many-body localized regime, similar to entanglement entropy. We also find that the tripartite information eventually reaches a plateau with an asymptotic value that is suppressed by strong disorder.

Automated summary

The tripartite information is a measure for the scattering and non-localization of information. It can be used as an indicator to distinguish between many-body localized and delocalized states. In the many-body localized regime, the tripartite information signal spreads within a light cone that grows logarithmically in time, similar to entanglement entropy. The tripartite information eventually reaches a plateau with an asymptotic value that is suppressed by strong disorder.