Quantum oscillation study of the large magnetoresistance in Mo substituted WTe2 single crystals

The list of interesting electrical properties exhibited by transition metal dichalcogenides has grown with the discovery of extremely large magnetoresistance (MR) and type-II Weyl semimetal behavior in WTe2 and MoTe2. The extremely large MR in WTe2 is still not adequately understood. Here, we systematically study the effect of Mo substitution on the quantum oscillations in the MR in WTe2. The MR decreases with Mo substitution, however, the carrier concentrations extracted from the quantum oscillations show that the charge compensation improves. We believe that earlier interpretations based on the two-band theory, which attribute the decrease in MR to charge imbalance, could be incorrect due to overparametrization. We attribute the decrease in MR in the presence of charge compensation to a fall in transport mobility, which is evident from the residual resistivity ratio data. The quantum scattering time and the effective masses do not change within experimental errors upon substitution.