Three-dimensional band structure of layered TiTe2: Photoemission final-state effects

Article

关键词: ENERGY-ELECTRON-DIFFRACTION;    SURFACE RESONANCES;    SPECTROSCOPY;    VLEED;    CU;    INTENSITIES;    RESOLUTION;    SOLIDS;    VSE2;    TIS2;   

DOI  :  10.1103/PhysRevB.74.195125

来源: SCIE

【 摘 要 】

Three-dimensional band structure of unoccupied and occupied states of the prototype layered material TiTe2 is determined focusing on the Gamma A line of the Brillouin zone. Dispersions and lifetimes of the unoccupied states, acting as the final states in the photoemission process, are determined from a very-low-energy electron diffraction experiment supported by first-principles calculations based on a Bloch waves treatment of multiple scattering. The experimental unoccupied states of TiTe2 feature dramatic non-free-electron effects such as multiband composition and nonparabolic dispersions. The valence band layer-perpendicular dispersions are then determined from a photoemission experiment consistently interpreted on the basis of the experimental final states to achieve control over the three-dimensional wave vector. The experimental results demonstrate the absence of the Te 4p(z)(*) Fermi surface pocket at the Gamma point and significant self-energy renormalization of the valence band dispersions. Photoemission calculations based on a Bloch waves formalism within the one-step theory reveal limitations of understanding photoemission from layered materials such as TiTe2 in terms of direct transitions.

【 授权许可】

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