Laser-induced topological phases in monolayer amorphous carbon

TL;DR

This paper demonstrates how circularly polarized laser light can induce and control topological phases in monolayer amorphous carbon, expanding topological engineering to non-crystalline materials.

Contribution

It introduces a feasible method to induce topological phases in amorphous materials using laser light and characterizes these phases with a novel topological marker.

Findings

Laser light induces edge modes at quasienergies 0 and ±π.

Topological phases depend on local atomic coordination.

Amorphous carbon can be engineered into topological phases.

Abstract

Driving non-topological materials out of equilibrium using time-periodic perturbations, such as circularly-polarized laser light, is a compelling way to engineer topological phases. At the same time, topology has traditionally only been considered for crystalline materials. Here we propose an experimentally feasible way of driving monolayer amorphous carbon topological.We show that circularly polarized laser light induces both regular and anomalous edge modes at quasienergies $0$ and $\pm \pi$, respectively. We also obtain a complete topological characterization using an energy- and space-resolved topological marker based on the spectral localizer. Additionally, by introducing atomic coordination defects in the amorphous carbon, we establish the importance of the local atomic coordination in topological amorphous materials. Our work establishes amorphous systems, including carbon, as a versatile and abundant playground to engineer topological phases.