Interlayer Charge-density-wave Vector Phase Induced Structural Chirality

TL;DR

This study uncovers how interlayer phase differences in charge density waves induce structural chirality in layered materials, combining first-principles calculations with experimental validation to predict and manipulate chiral CDW states.

Contribution

It introduces the interlayer phase as a key factor in chiral CDW formation and demonstrates its role through first-principles calculations and experimental consistency.

Findings

Chiral structures of AV3Sb5 and 1T-TiSe2 are successfully predicted.

Electronic and optical properties match experimental observations.

1T-NbSe2 is identified as a candidate for chiral CDW realization.

Abstract

Chiral charge density waves (CDWs) have attracted intense interest due to their exotic quantum properties, yet the microscopic origin of structural chirality emerging from correlated charge order remains elusive. Here, we reveal that the interlayer phases of CDW wave vectors, an overlooked degree of freedom, play a crucial role in driving chiral structural displacements in layered CDW materials. By explicitly incorporating the interlayer phases in first-principles calculations, we successfully obtained the chiral structure of the CDW phases of AV$_3$Sb$_5$ (A= K, Rb, and Cs) and 1T-TiSe$_2$. The electronic and optical properties of the predicted chiral structures are consistent with experimental measurements of these materials in their CDW phases. We further predict that 1T-NbSe$_2$ is a promising material candidate for realizing chiral CDW order. Beyond materials prediction, our theory reveals that the chiral CDW can be manipulated by electron filling. Our study opens new avenues for discovering, designing, and engineering chiral CDW materials.