3D-to-2D transition by Cs intercalation ofVSe2

Abstract

Angle-resolved photoemission spectroscopy has been employed to study in situ intercalation of the layered compound ${\mathrm{VSe}}_2$ with Cs. The results show that the valence band structure of ${\mathrm{VSe}}_2$, which initially is of 3D character, is transformed to become essentially 2D upon Cs intercalation. The changes, which go far beyond the rigid-band model, are successfully reproduced by self-consistent linear-augmented-plane-wave calculations. This is the first report of a UHV compatible system where the dimensionality of the electronic structure can be controlled in situ.