Superconducting and structural properties of the type-I superconductor PdTe2 under high pressure

Abstract

The transition metal dichalcogenide PdTe${}_2$ has attractive features based on its classification as a type-II Dirac semimetal and the occurrence of type-I superconductivity, providing a platform for discussion of a topological superconductor. Our recent work revealed that type-I superconductivity persists up to pressures of $\sim 2.5$ GPa and the superconducting transition temperature $T_{\mathrm{c}}$ reaches a maximum at around 1 GPa, which is inconsistent with the theoretical prediction. To understand its non-monotonic variation and investigate superconductivity at higher pressures, we performed structural analysis by x-ray diffraction at room temperature below 8 GPa and electrical resistivity measurements at low temperatures from 1 to 8 GPa. With regard to the superconductivity beyond 1 GPa, the monotonic decrease in $T_{\mathrm{c}}$ is reproduced without any noticeable anomalies; $T_{\mathrm{c}}$ changes from 1.8 K at 1 GPa to 0.82 K at 5.5 GPa with $d{T}_{\mathrm{c}}/dP\sim -0.22$ K/GPa. The crystal structure with spacegroup $P$\={3}$m$1 is stable in the pressure range we examined. On the other hand, the normalized pressure-strain analysis (finite strain analysis) indicates that the compressibility changes around 1 GPa, suggesting that a Lifshitz transition occurs. We here discuss the effect of pressure on the superconducting and structural properties based on the comparison of these experimental results.

References in corpus (9)

• Type-II Dirac fermions in the PtSe${}_2$ class of transition metal dichalcogenides
• Type I superconductivity in the Dirac semimetal PdTe2
• Conventional Superconductivity in Type II Dirac Semimetal PdTe${}_2$
• Type-I superconductivity in PdTe${}_2$ probed by $\mu$SR
• Single full gap with mixed type-I and type-II superconductivity on surface of the type-II Dirac semimetal PdTe2 by point-contact spectroscopy
• Dominant $s$-wave superconducting gap in PdTe${}_2$ observed by tunneling spectroscopy on side-junctions
• Anomalous charge transport of superconducting Cu${}_x$PdTe${}_2$ under high pressure
• Heat capacity of type I superconductivity in the Dirac semimetal PdTe${}_2$
• Scattering rate collapse driven by a van Hove singularity in the Dirac semi-metal PdTe${}_2$

Cited by in corpus (1)

• Disorder induced transition from type-I to type-II superconductivity in the Dirac semimetal PdTe${}_2$