Topological phase transition in the quench dynamics of a one-dimensional Fermi gas

TL;DR

This paper investigates the dynamical behavior of a one-dimensional ultracold Fermi gas with spin-orbit coupling, revealing a dynamical phase transition linked to topological properties and Majorana edge states after a quench.

Contribution

It uncovers a novel dynamical phase transition in quenched Fermi gases and demonstrates its topological origin through edge-state analysis.

Findings

Identification of a dynamical phase transition characterized by a sudden change in pairing gap.

Demonstration of the topological nature of the transition via edge-state analysis.

Potential for dynamical detection of Majorana edge states in ultracold gases.

Abstract

We study the quench dynamics of a one-dimensional ultracold Fermi gas in an optical lattice potential with synthetic spin-orbit coupling. At equilibrium, the ground state of the system can undergo a topological phase transition and become a topological superfluid with Majorana edge states. As the interaction is quenched near the topological phase boundary, we identify an interesting dynamical phase transition of the quenched state in the long-time limit, characterized by an abrupt change of the pairing gap at a critical quenched interaction strength. We further demonstrate the topological nature of this dynamical phase transition from edge-state analysis of the quenched states. Our findings provide interesting clues for the understanding of topological phase transitions in dynamical processes, and can be useful for the dynamical detection of Majorana edge states in corresponding systems.