Hidden spin-polarized bands in semiconducting 2H-MoTe2

Abstract

We present experimental and theoretical studies of the electronic band structure of 2H-MoTe2 at high hydrostatic pressures. Photoreflectance measurements allowed the determination of the pressure coefficient of the direct transitions A and B, which are 2.40(3) and −3.42(18) meV/kbar, respectively. We attribute the sign difference to a strong splitting of the conduction bands with increasing pressure and the presence of hidden spin-polarized states in bulk MoTe2. These results provide direct experimental evidence that the spin–valley locking effect takes place in centrosymmetric transition metal dichalcogenides.

Keywords

• transition metal dichalcogenides
• photoreflectance
• spin–valley locking
• density functional theory
• two-dimensional materials