Quantum anomalous Hall domains in a Quenched Topological Mott Insulator

TL;DR

This paper investigates the dynamics of a topological Mott insulator after a quench, revealing the formation of QAH domains with chiral edge currents through time-dependent simulations.

Contribution

It introduces a novel study of quench dynamics in a topological Mott insulator, showing spontaneous formation of QAH domains and chiral currents.

Findings

Post-quench, the system becomes an excited Dirac semimetal.

Inhomogeneous stripe patterns of nematic and QAH order develop.

QAH domains with chiral sublattice currents emerge over time.

Abstract

We study an interacting spinless quadratic band touching model that realizes a topological Mott insulating state. We quench the interaction from a value corresponding to the nematic insulator to that of the quantum anomalous Hall (QAH) ordered phase. We perform time-dependent Hartree-Fock simulations and show that after the quench the system realizes an excited Dirac semimetal state, which is however unstable and spontaneously evolves to a state with inhomogeneous nematic and QAH order parameters. The modulations form a stripe pattern that grows exponentially with time until the local Chern marker reaches unity. The alternating QAH order defines a domain structure with boundaries that host chiral sublattice currents.