Dynamical Topological Transitions in the Massive Schwinger Model with a θ Term

Abstract

Aiming at a better understanding of anomalous and topological effects in gauge theories out-ofequilibrium, we study the real-time dynamics of a prototype model for CP-violation, the massive Schwinger model with a θ-term. We identify dynamical quantum phase transitions between different topological sectors that appear after sufficiently strong quenches of the θ-parameter. Moreover, we establish a general dynamical topological order parameter, which can be accessed through fermion two-point correlators and, importantly, which can be applied for interacting theories. Enabled by this result, we show that the topological transitions persist beyond the weak-coupling regime. Finally, these effects can be observed with table-top experiments based on existing coldatom, superconducting-qubit, and trapped-ion technology. Our work, thus, presents a significant step towards quantum simulating topological and anomalous real-time phenomena relevant to nuclear and high-energy physics.

QCD thermalization: Ab initio approaches and interdisciplinary connections

“…Anomalies have been investigated for Abelian theories off-equilibrium for the fully dynamical situation, including the back-reaction of the fermions onto the gauge fields, in one [360,361], two [362] and three [363,364] spatial dimensions. In Refs.…”

“…In Refs. [360,361] dynamical topological transitions in the massive Schwinger Model with a θ-term as a prototype model for CP-violation, are studied. A dynamical order parameter for quantum phase transitions between different topological sectors is established, that can be accessed through fermion two-point correlators.…”

“…A dynamical order parameter for quantum phase transitions between different topological sectors is established, that can be accessed through fermion two-point correlators. Using exact diagonalization techniques, the topological transitions have been shown to persist beyond the weak-coupling regime [360].…”

Real-time-dynamics quantum simulation of (1+1)-dimensional lattice QED with Rydberg atoms

“…Remarkably, we compared the dynamics of the Z 3 model with that of the U (1) gauge theory, finding qualitative similarities in the string dynamics. Our quantum simulator is therefore a versatile and reliable experimental setup useful for investigating exotic properties of discrete and continuous Abelian lattice gauge theories [40,41]. Possible outlook for this work is the extension to two-dimensional theories, in continuity with a recent proposal about the study of 2D pure gauge systems [42], as well as the application of this protocol for simulating clock variables to different models such as time crystals [43,44].…”

Out-of-time-order correlations and Floquet dynamical quantum phase transition

“…In DQPT the real time acts as a control parameter analogous to temperature in conventional equilibrium phase transitions. The DQPT characterized by the nonanalytical behavior of dynamical free energy [47,51,75,76,83,[88][89][90][91][92][93][94][95] which is defined as…”