2023/10/12 by Chengcheng Zhao, Zhao, Chengcheng, Xiangqi Liu +41 · 1 citation
Physics and Astronomy · Materials Science · #Topological Materials and Phenomena #Graphene research and applications #Chemical and Physical Properties of Materials
paper · pdf · doi:10.48550/arxiv.2310.08462
Recently PdTe was identified as a spin-orbit coupled topological Dirac semimetal and was claimed to exhibit both bulk-nodal and surface-nodeless superconducting gaps. Here we report the ultralow-temperature thermal conductivity measurements on PdTe single crystals with Tc = 4.5 K to investigate its superconducting gap structure. It is found that the residual linear term κ0/T is negligible in zero magnetic field. Furthermore, the field dependence of κ0(H)/T exhibits an \sf S-shaped curve. These results suggest that PdTe has multiple nodeless superconducting gaps, which is at odds with the claimed bulk-nodal gap. The reason for the discrepancy is likely that previous angle-resolved photoemission spectroscopy measurements were only performed down to 2 K and cannot observe the smaller nodeless gap. The fully gapped superconducting state in PdTe is compatible with it being a topological superconductor candidate.