paper

Incommensurate Chiral CDW in $1 T$ -VSe $_{2}$

arXiv:1812.01368

Abstract

We have investigated the chiral charge-density wave (CDW) in $1 T$ -VSe $_{2}$ using scanning tunneling microscopy (STM) measurements and optical polarimetry measurements. With the STM mesurements, we revealed that the CDW intensities along each triple- $q$ directions are different. Thus the rotational symmetry of $1 T$ -VSe $_{2}$ is lower than that in typical two-dimentional triple- $q$ CDWs. We found that the CDW peaks form a kagome lattice rather than a triangular lattice. The Friedel oscillations have the chirality and the periodicity reflected properties of the background CDW. With the optical measurements in $1 T$ -VSe $_{2}$ , we also observed a lower rotational symmetry with the polarization dependence of the transient reflectivity variation, which is consistent with the STM result on a microscopic scale. Both $1 T$ -TiSe $_{2}$ and $1 T$ -VSe $_{2}$ show chiral CDWs, which implies that such waves are usual for CDWs with the condition $H_{CDW} \equiv q_{1} \cdot (q_{2} \times q_{3}) \neq = 0$ .

15 pages, 5 figures, 1 Table

Incommensurate Chiral CDW in 1T-VSe2​

Abstract

Incommensurate Chiral CDW in $1 T$ -VSe $_{2}$