Anomalous charge transport of superconducting Cu$_{x}$PdTe$_2$ under high pressure

Abstract

By means of high-pressure resistivity measurements on single crystals, we investigate the charge transport properties of Cu x PdTe 2 , notable for the combination of topological type-II Dirac semimetallic properties with superconductivity up to T c = 2.5 K. In both cases of pristine (x = 0) and intercalated (x = 0.05) samples, we find an unconventional T 4 power law behavior of the low-temperature resistivity visible up to ∼40 K and remarkably stable under pressure up to 8.2 GPa. This observation is explained by the low carrier density n, which strongly reduces the k-region available for electron-phonon scattering, as previously reported in other low-n two-dimensional systems, such as multilayer graphene and semiconductor heterostructures.Our data analysis complemented by specific heat measurements and supported by previous quantum oscillation studies and ab initio calculations suggests a scenario of one-band charge transport. Within this scenario, our analysis yields a large value of transport electron-phonon coupling constant λ tr = 1.2 at ambient pressure that appears to be strongly enhanced by pressure assuming a constant effective mass.