Elastic and electronic tuning of magnetoresistance in MoTe.

Quasi-two-dimensional transition metal dichalcogenides exhibit dramatic properties that may transform electronic and photonic devices. We report on how the anomalously large magnetoresistance (MR) observed under high magnetic field in MoTe, a type II Weyl semimetal, can be reversibly controlled under tensile strain. The MR is enhanced by as much as ~30% at low temperatures and high magnetic fields when uniaxial strain is applied along the crystallographic direction and reduced by about the same amount when strain is applied along the direction. We show that the large in-plane electric anisotropy is coupled with the structural transition from the 1T' monoclinic to the T orthorhombic Weyl phase. A shift of the T-1T' phase boundary is achieved by minimal tensile strain. The sensitivity of the MR to tensile strain suggests the possibility of a nontrivial spin-orbital texture of the electron and hole pockets in the vicinity of Weyl points. Our ab initio calculations show a significant orbital mixing on the Fermi surface, which is modified by the tensile strains.