Local quenches in frustrated quantum spin chains: global vs. subsystem equilibration

Understand

We study the equilibration behavior following local quenches, using frustrated quantum spin chains as an example of interacting closed quantum systems.

• Specifically, we examine the statistics of the time series of the Loschmidt echo, the trace distance of the time-evolved local density matrix to its average state, and the local magnetization.
• Depending on the quench parameters, the equilibration statistics of these quantities show features of good or poor equilibration, indicated by Gaussian, exponential or bistable distribution functions.
• These universal functions provide valuable tools to characterize the various time-evolution responses and give insight into the plethora of equilibration phenomena in complex quantum systems.