The interplay between topology, defects and chiral order in the nearly-commensurate charge density wave of 1T-TaS2

TL;DR

This study investigates how topological defects influence chiral order in the nearly-commensurate charge density wave of 1T-TaS2, revealing mechanisms for controllable room-temperature chirality through strain and electric fields.

Contribution

It introduces a holographic analysis linking topological defects to chiral order, providing new insights into defect-driven chirality control in 1T-TaS2.

Findings

Distinct topological defects identified in CDW order

Strain induces vortex nucleation and annihilation

Electric fields enable controllable chiral switching

Abstract

In 1T-TaS2, the nearly-commensurate charge density wave (NC-CDW) exhibits emergent chirality, a property of interest for technological applications such as memory. We study the relationship between chirality and topological defects using holographic analysis of scanning tunneling microscopy data. By characterizing the CDW order parameter, we uncover distinct topological defects and define a chiral order parameter that connects directly to them. Our analysis distinguishes between vortex pairs in high-strain areas and glass-like soliton or discommensurations networks. We propose that perturbations, such as strain, drive vortex nucleation and annihilation, leaving solitons or discommensurations pinned by disorder. Electric fields induce soliton and discommensurations movement, causing chiral switching via localized order parameter melting, enabling controllable room-temperature chirality