Terahertz response of monolayer and few-layer WTe₂ at the nanoscale.

ABSTRACT: Tungsten ditelluride (WTe₂) is an atomically layered transition metal dichalcogenide whose physical properties change systematically from monolayer to bilayer and few-layer versions. In this report, we use apertureless scattering-type near-field optical microscopy operating at Terahertz (THz) frequencies and cryogenic temperatures to study the distinct THz range electromagnetic responses of mono-, bi- and trilayer WTe₂ in the same multi-terraced micro-crystal. THz nano-images of monolayer terraces uncovered weakly insulating behavior that is consistent with transport measurements. The near-field signal on bilayer regions shows moderate metallicity with negligible temperature dependence. Subdiffractional THz imaging data together with theoretical calculations involving

SUBMITTER: Jing R 

PROVIDER: S-EPMC8458490 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature