Spin-resolved electronic response to the phase transition in MoTe$_2$

TL;DR

This study uses spin- and angle-resolved photoemission spectroscopy to reveal complex spin textures and surface Fermi arcs in MoTe$_2$, highlighting persistent spin features and electron-lattice interactions across its phase transition.

Contribution

It uncovers a novel three-dimensional spin texture in MoTe$_2$'s bulk Fermi surface and demonstrates the persistence of surface Fermi arcs above the phase transition.

Findings

Discovery of a complex 3D spin texture in bulk MoTe$_2$

Persistence of surface Fermi arcs above the transition temperature

Enhanced electron quasiparticle lifetimes during initial cooling

Abstract

The semimetal MoTe$_2$ is studied by spin- and angle- resolved photoemission spectroscopy to probe the detailed electronic structure underlying its broad range of response behavior. A novel spin-texture is uncovered in the bulk Fermi surface of the non-centrosymmetric structural phase that is consistent with first-principles calculations. The spin-texture is three-dimensional, both in terms of momentum dependence and spin-orientation, and is not completely suppressed above the centrosymmetry-breaking transition temperature. Two types of surface Fermi arc are found to persist well above the transition temperature. The appearance of a large Fermi arc depends strongly on thermal history, and the electron quasiparticle lifetimes are greatly enhanced in the initial cooling. The results indicate that polar instability with strong electron-lattice interactions exists near the surface when the bulk is largely in a centrosymmetric phase.