√3 × 2 and √3 × √7 Charge Density Wave Driven by Lattice Distortion in Monolayer VSe2

Trinh Thi Ly, Ganbat Duvjir, Nguyen Huu Lam, Jungdae Kim, Byoung Ki Choi, Young Jun Chang

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

A charge density wave (CDW), an ordered modulation of electron distribution and lattice distortion, is one of the intriguing phenomena observed in transition metal dichalcogenides. Recent STM studies reported a new CDW phase with √3 × 2 and √3 × √7 periodicities in monolayer (ML) VSe2 grown on graphene, which is totally different from the 4 x 4 x 3 CDW periodicity in bulk. Although the emergence of new CDW phase is of great research interest, the origin of the new modulation in ML VSe2 has not been clearly investigated. In this report, we conduct a systematic study to understand the nature of the √3 × 2 and √3 × √7 CDW in ML VSe2 using scanning tunneling microscopy (STM). Bias dependent topography and differential conductance (dI/dV) mapping indicate that the √3 × 2 and √3 × √7 modulations are mostly driven by strong lattice distortions of the Se atoms rather than by charge orderings. In addition, STM topography reveals that the v3 × 2 modulation corresponds to a gap feature, and the v3 × v7 modulation corresponds to an isolated Se atom in the distorted lattice structures. Our work provides prerequisite information to understand the emergence of √3, × 2 and √3, × √7 CDW in ML VSe2.

Original languageEnglish
Pages (from-to)412-415
Number of pages4
JournalJournal of the Korean Physical Society
Volume76
Issue number5
DOIs
StatePublished - 1 Mar 2020

Keywords

  • Charge density wave
  • Lattice distortion
  • STM
  • VSe

Fingerprint

Dive into the research topics of '√3 × 2 and √3 × √7 Charge Density Wave Driven by Lattice Distortion in Monolayer VSe2'. Together they form a unique fingerprint.

Cite this