Laser-beam patterned topological insulating states on thin semiconducting MoS2

TL;DR

This paper demonstrates laser-beam patterning to induce and control topological insulating states in thin MoS2, revealing quantum spin Hall phases with potential for spintronic applications.

Contribution

It introduces a novel laser patterning technique to create and manipulate topological phases in MoS2, advancing 2D topological insulator research.

Findings

Observation of quantum spin Hall phase in patterned MoS2

Control of topological states via laser irradiation conditions

Detection of bulk gap through spectroscopy and calculations

Abstract

Identifying the two-dimensional (2D) topological insulating (TI) state in new materials and its control are crucial aspects towards the development of voltage-controlled spintronic devices with low power dissipation. Members of the 2D transition metal dichalcogenides (TMDCs) have been recently predicted and experimentally reported as a new class of 2D TI materials, but in most cases edge conduction seems fragile and limited to the monolayer phase fabricated on specified substrates. Here, we realize the controlled patterning of the 1T'-phase embedded into the 2H-phase of thin semiconducting molybdenum-disulfide (MoS2) by laser beam irradiation. Integer fractions of the quantum of resistance, the dependence on laser-irradiation conditions, magnetic field, and temperature, as well as the bulk gap observation by scanning tunneling spectroscopy and theoretical calculations indicate the presence of the quantum spin Hall phase in our patterned 1T' phases.