Towards large-Chern-number topological phases by periodic quenching

TL;DR

This paper presents a method to generate large-Chern-number topological phases in two-band systems through periodic quenching, enabling tunable topological properties in Floquet systems.

Contribution

It introduces a simple scheme to engineer large-Chern-number phases via periodic quenching between two basic Hamiltonians, expanding the toolkit for topological phase control.

Findings

Large Chern numbers achieved through periodic quenching.

Multiple Dirac cones explain the topological phase transitions.

Explicit phase transition lines identified in the model.

Abstract

Topological phases with large Chern numbers have important implications. They were previously predicted to exist by considering fabricated long-range interactions or multi-layered materials. Stimulated by recent wide interests in Floquet topological phases, here we propose a scheme to engineer large-Chern-number phases with ease by periodic quenching. Using a two-band system as an example, we theoretically show how a variety of topological phases with widely tunable Chern numbers can be generated by periodic quenching between two simple Hamiltonians that otherwise give low Chern numbers. The obtained large Chern numbers are explained through the emergence of multiple Dirac cones in the Floquet spectra. The transition lines between different topological phases in the two-band model are also explicitly found, thus establishing a class of easily solvable but very rich systems useful for further understandings and applications of topological phases in periodically driven systems.