| AVS 65th International Symposium & Exhibition | |
| Magnetic Interfaces and Nanostructures Division | Friday Sessions |
| Session MI+EM-FrM |
| Session: | Magnetism and Spin-Orbit Coupling at Surfaces, Interfaces and Thin Films |
| Presenter: | Markus Donath, Westfälische Wilhelms-Universität Münster, Germany |
| Authors: | M. Donath, Westfälische Wilhelms-Universität Münster, Germany P. Eickholt, Westfälische Wilhelms-Universität Münster, Germany J. Noky, Westfälische Wilhelms-Universität Münster, Germany E. Schwier, Hiroshima University, Japan K. Shimada, Hiroshima University, Japan K. Miyamoto, Hiroshima University, Japan T. Okuda, Hiroshima University, Japan C. Datzer, Westfälische Wilhelms-Universität Münster, Germany M. Drüppel, Westfälische Wilhelms-Universität Münster, Germany P. Krüger, Westfälische Wilhelms-Universität Münster, Germany M. Rohlfing, Westfälische Wilhelms-Universität Münster, Germany |
| Correspondent: | Click to Email |
Transition-metal dichalcogenides (TMDCs) are a focus of current research due to their fascinating optical and electronic properties with possible technical applications. ReSe2 is an interesting material of the TMDC family, with unique anisotropic properties originating from its distorted 1T structure (1T’). To develop a fundamental understanding of the optical and electric properties, we studied the underlying electronic structure with angle-resolved photoemission (ARPES) as well as band-structure calculations within the density functional theory (DFT)–local density approximation (LDA) and GdW approximations [1]. We observe anisotropic valence-band dispersions parallel to the surface. We find that along ΓM1, which is the direction perpendicular to the "diamond" chains, the bandwidth of the hightest valence band is significantly smaller than in any other direction. Photon-energy-dependent measurements reveal a kz-dependent band dispersion, reflecting the interlayer coupling. Two valence band maxima are identified within experimental limits of about 50 meV: one at the high-symmetry point Z, and a second one at a non-high-symmetry point in the Brillouin zone. Thus, the position in k space of the global valence band maximum is undecided experimentally. Theoretically, an indirect band gap is predicted on a DFT-LDA level, while quasiparticle corrections lead to a direct band gap at the Z point.
[1] P. Eickholt et al., Phys. Rev. B 97, 165130 (2018).