Control of the MoTe$_2$ Fermi Surface by Nb Doping
/ Authors
Andrew P. Weber, I. Robredo, P. Russmann, M. Ilyn, Arnaud Magrez, P. Bugnon, Nan Xu, V. Strocov, J. Dil, J. Ortega
and 12 more authors
Julen Ibanez-Azpiroz Donostia International Physics Center, ICFO-Institut de Ciencies Fotoniques, Luxembourg Institute of Science, Technology, Forschungszentrum Julich, Centro de F'isica de Materiales CSIC-UPVEHU, 'Ecole polytechnique f'ed'erale de Lausanne, Wuhan University, Wuhan University of Technology, P. Institute, Universidad del Pa'is Vasco, Ikerbasque Foundation
/ Abstract
Ab initio calculations and angle-resolved photoemission experiments show that the bulk and surface electronic structure of Weyl semimetal candidate MoTe$_2$ changes significantly by tuning the chemical potential by less than 0.4 eV. Calculations show that several Lifshitz transitions can occur among multiple electron and hole Fermi pockets of differing orbital character. Experiments show that 18% Nb-Mo substitution reduces the occupation of bulk and (001) surface bands, effectively producing a chemical potential shift of $\approx 0.3$ eV. Orbital character and dimensionality of the bulk bands is examined by soft X-ray angle resolved photoemission with control of the excitation light polarization. The band filling at the surface is shown to increase upon deposition of alkali atoms. The results indicate that multiple regimes of electronic properties can be easily accessed in this versatile, layered material.