A thermodynamic probe of the topological phase transition in epitaxial graphene based Floquet topological insulator

TL;DR

This paper investigates how thermodynamic measurements like efficiency and work output of quantum heat engines can detect topological phase transitions in epitaxial graphene-based Floquet topological insulators, showing robustness against light polarization.

Contribution

It introduces a thermodynamic approach to identify topological phase transitions in FTIs using quantum heat engine metrics, a novel method in this context.

Findings

Efficiency and work output exhibit extrema at the phase transition point.

The thermodynamic signals are robust against light polarization.

Quantum heat engines can serve as probes for topological phases.

Abstract

One can use light to tune certain materials, from a trivial to a topological phase. A prime example of such materials, classified as Floquet topological insulators (FTI), is epitaxial graphene. In this paper, we probe the topological phase transition of an FTI via the efficiency and work output of quantum Otto and quantum Stirling heat engines. A maximum/minimum in the efficiency or work output invariably signals the phase transition point. Further, both engines' work output and efficiency are markedly robust against the polarization direction of light.