Quasi-2D Transport and Weak Antilocalization Effect in Few-layered VSe.

With strong spin-orbit coupling (SOC), ultrathin two-dimensional (2D) transitional metal chalcogenides (TMDs) are predicted to exhibit weak antilocalization (WAL) effect at low temperatures. The observation of WAL effect in VSe is challenging due to the relative weak SOC and three-dimensional (3D) transport nature in thick VSe. Here, we report on the observation of quasi-2D transport and WAL effect in sublimed-salt-assisted low-temperature chemical vapor deposition (CVD) grown few-layered high-quality VSe nanosheets. The WAL magnitudes in magnetoconductance can be perfectly fitted by the 2D Hikami-Larkin-Nagaoka (HLN) equation in the presence of strong SOC, by which the spin-orbit scattering length and phase coherence length have been extracted. The phase coherence length shows a power law dependence with temperature, ∼ , revealing an electron-electron interaction-dominated dephasing mechanism. Such sublimed-salt-assisted growth of high-quality few-layered VSe and the observation of WAL pave the way for future spintronic and valleytronic applications.