Direct observation of dynamical quantum phase transitions in an interacting many-body system

TL;DR

This paper reports the direct observation of dynamical quantum phase transitions in an interacting many-body system of trapped ions, linking non-equilibrium dynamics, magnetization, and entanglement.

Contribution

It demonstrates the detection of DQPTs in a controllable ion system and connects these transitions to magnetization dynamics and entanglement growth.

Findings

Detection of non-analytic behavior in a measurable quantity during DQPTs

Observation of DQPTs in systems of up to 10 ions

Established links between DQPTs, magnetization, and entanglement

Abstract

Dynamical quantum phase transitions (DQPTs) extend the concept of phase transitions and thus universality to the non-equilibrium regime. In this letter, we investigate DQPTs in a string of ions simulating interacting transverse-field Ising models. We observe non-equilibrium dynamics induced by a quantum quench and show for strings of up to 10 ions the direct detection of DQPTs by measuring a quantity that becomes non-analytic in time in the thermodynamic limit. Moreover, we provide a link between DQPTs and the dynamics of other relevant quantities such as the magnetization, and we establish a connection between DQPTs and entanglement production.