Mitrofanovite Pt<sub>3</sub>Te<sub>4</sub>: A Topological Metal with Termination-Dependent Surface Band Structure and Strong Spin Polarization.

Fujii, Jun; Ghosh, Barun; Vobornik, Ivana; Bari Sarkar, Anan; Mondal, Debashis; Kuo, Chia-Nung; Bocquet, François C; Zhang, Lixue et al. · ACS Nano · 2021

basic_science · Level V

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Abstract

Due to their peculiar quasiparticle excitations, topological metals have high potential for applications in the fields of spintronics, catalysis, and superconductivity. Here, by combining spin- and angle-resolved photoemission spectroscopy, scanning tunneling microscopy/spectroscopy, and density functional theory, we discover surface-termination-dependent topological electronic states in the recently discovered mitrofanovite Pt<sub>3</sub>Te<sub>4</sub>. Mitrofanovite crystal is formed by alternating, van der Waals bound layers of Pt<sub>2</sub>Te<sub>2</sub> and PtTe<sub>2</sub>. Our results demonstrate that mitrofanovite is a topological metal with termination-dependent (i) electronic band structure and (ii) spin texture. Despite their distinct electronic character, both surface terminations are characterized by electronic states exhibiting strong spin polarization with a node at the Γ point and sign reversal across the Γ point, indicating their topological nature and the possibility of realizing two distinct electronic configurations (both of them with topological features) on the surface of the same material.