Unusual Pressure-Induced Quantum Phase Transition from Superconducting to Charge-Density Wave State in Rare-Earth-Based Heusler LuPd2In Compound

Abstract

We investigate the pressure effects on the electronic structures and phonon properties of rare-earth-based cubic-Heusler compound LuPd2In, on the basis of ab initio density functional theory. We find the occurrence of intriguing phase transition from the superconducting (SC) to charge-density wave (CDW) state under pressure (P), which is quite unusual in that the pressure is detrimental to the CDWstate in usual systems. The SC transition temperature T-C of LuPd2In increases first with increasing pressure, up to P-C approximate to 28 GPa, above which a quantum phase transition into the CDW state takes place. This extraordinary transition originates from the occurrence of phonon softening instability at a special q = M in the Brillouin zone. We thus propose that LuPd2 In is a quite unique material, in which the CDW quantum critical point is realized under the SC dome by applying the pressure.