Surface band characters of Weyl semimetal candidate material MoTe$_2$ revealed by one-step ARPES theory

TL;DR

This study combines ARPES experiments, density functional theory, and one-step ARPES calculations to analyze the surface band characters of MoTe$_2$, a candidate Weyl semimetal, revealing how light polarization affects observable bands.

Contribution

It provides a detailed analysis of the surface band characters of MoTe$_2$ and demonstrates the importance of light polarization in ARPES measurements for topological materials.

Findings

Good agreement between ARPES measurements and theoretical calculations.

Light polarization significantly influences which surface bands are observed.

Identification of optimal polarization conditions for observing electron and hole pockets.

Abstract

The layered 2D-material MoTe$_2$ in the T$_d$ crystal phase is a semimetal which has theoretically been predicted to possess topologically non-trivial bands corresponding to Weyl fermions. Clear experimental evidence by angle-resolved photoemission spectroscopy (ARPES) is, however, lacking, which calls for a careful examination of the relation between ground state band structure calculations and ARPES intensity plots. Here we report a study of the near Fermi-energy band structure of MoTe$_2$(T$_d$) by means of ARPES measurements, density functional theory, and one-step-model ARPES calculations. Good agreement between theory and experiment is obtained. We analyze the orbital character of the surface bands and its relation to the ARPES polarization dependence. We find that light polarization has a major efect on which bands can be observed by ARPES. For s-polarized light, the ARPES intensity is dominated by subsurface Mo d orbitals, while p-polarized light reveals the bands composed mainly derived from Te p orbitals. Suitable light polarization for observing either electron or hole pocket are determined