Theory of Raman scattering from the orthorhombic commensurate phase of 2H-TaSe2

Abstract

The experimentally observed Raman scattering data on 2H-TaSe2 has been reanalyzed in the light of the recent discovery that the commensurate superlattice has orthorhombic and not hexagonal symmetry. A recent model for the orthorhombic, commensurate phase can be consistent with the observed Raman spectra only if the interlayer interactions are weak. Similarly, the weakly interacting charge-density-wave picture is shown to be incorrect and, consequently, amplitude and phase modes are, in general, coupled. Show more