Dynamical quantum phase transitions in the random field Ising model

TL;DR

This paper investigates dynamical quantum phase transitions in the random field Ising model, revealing potential universality of singularities in time and their relevance to many-body localized systems.

Contribution

It analytically describes the singularities in the random field Ising model, suggesting their broader presence in various quantum systems including many-body localized ones.

Findings

Singularities occur in the random field Ising model during time evolution.

Analytical description of these dynamical singularities is provided.

Potential universality of these phenomena across different quantum systems.

Abstract

Over the last few years it was pointed out that certain observables of time-evolving quantum systems may have singularities at certain moments in time, mimicking the singularities physical systems have when undergoing phase transitions. These were given the name of dynamical phase transitions. They were shown to exist in certain integrable (exactly solvable) quantum systems, and were seen experimentally in some setups related (but not identical) to these solvable models. The "universality classes" of such singularities were not yet convincingly established, however. We argue that random field Ising models feature singularities in time which may potentially be present in a wider variety of quantum systems, in particular in those which are many body localized, and describe these singularities in detail analytically.