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

• Published in: arXiv.org
• Main Authors: Furue, Yusaku, Fujino, Tadachika, Salis, Marc V, Leng, Huaqian, Ishikawa, Fumihiro, Naka, Takashi, Nakano, Satoshi, Huang, Yingkai, de Visser, Anne, Ohmura, Ayako
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 11.08.2021
• Subjects: Anomalies; Compressibility; Crystal structure; Low temperature; Physics - Superconductivity; Pressure effects; Room temperature; Strain analysis; Structural analysis; Superconductivity; Topological superconductors; Transition metal compounds; Transition temperature
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2108.05304

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 \(\sim2.5\) GPa and the superconducting transition temperature \(T_{\rm c}\) 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 \(T_{\rm c}\) is reproduced without any noticeable anomalies; \(T_{\rm c}\) changes from 1.8 K at 1 GPa to 0.82 K at 5.5 GPa with \(dT_{\rm c}/dP\sim-0.22\) 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.