Supersymmetric non-Hermitian topological interface laser

TL;DR

This paper explores topological interface lasers in a non-Hermitian Su-Schrieffer-Heeger model, revealing localized modes, SUSY partner states, and the potential for large-area coherent laser emission.

Contribution

It introduces a novel analysis of topological interface states with non-Hermiticity and nonlinearity, including SUSY-based solutions and laser operation insights.

Findings

Localized Jackiw-Rebbi mode with imaginary energy

Analytic excited states based on SUSY quantum mechanics

Potential for large-area coherent laser emission

Abstract

We investigate laser emission at the interface of a topological and trivial phases with loss and gain. The system is described by a Su-Schrieffer-Heeger model with site-dependent hopping parameters. We study numerically and analytically the interface states. The ground state is described by the Jackiw-Rebbi mode with a pure imaginary energy, reflecting the non-Hermiticity of the system. It is strictly localized only at the A sites. We also find a series of analytic solutions of excited states based on SUSY quantum mechanics, where the A and B sites of the bipartite lattice form SUSY partners. We then study the system containing loss and gain with saturation. The Jackiw-Rebbi mode is extended to a nonlinear theory, where B sites are also excited. The relative phases between A and B sites are fixed, and hence it will serve as a large area coherent laser.