Ultrahigh-resolution angle-resolved photoemission study of LaX (X=S, Se, Te)

Abstract

Systematic study of the energy band structures for LaX (X=S, Se, Te) was carried out by ultrahigh-resolution angle-resolved photoemission spectroscopy . The band gap between the conduction and valence bands was clearly observed in every LaX. The conduction and valence bands show the systematic changes from LaS to LaTe with regard to their energy positions and band widths .