Multiband nodeless superconductivity near the charge-density-wave quantum critical point in ZrTe_3–xSe_x

Journal Article · 09 June 2016 · Chinese Physics. B

DOI: https://doi.org/10.1088/1674-1056/25/7/077403 · OSTI ID:1345739

Cui, Shan ^[1]; He, Lan -Po ^[1]; Hong, Xiao -Chen ^[1]; Zhu, Xiang -De ^[2]; Petrovic, Cedomir ^[3]; Li, Shi -Yan ^[4]

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1. Fudan Univ., Shanghai (China)
2. Chinese Academy of Sciences and Univ. of Science and Technology of China, Hefei (China); Brookhaven National Lab. (BNL), Upton, NY (United States)
3. Brookhaven National Lab. (BNL), Upton, NY (United States)
4. Fudan Univ., Shanghai (China); Collaborative Innovation Center of Advanced Microstructures, Nanjing (China)

It was found that selenium doping can suppress the charge-density-wave (CDW) order and induce bulk superconductivity in ZrTe₃. The observed superconducting dome suggests the existence of a CDW quantum critical point (QCP) in ZrTe_3–x Se_x near x ≈ 0.04. To elucidate the superconducting state near the CDW QCP, we measure the thermal conductivity of two ZrTe_3–x Se_x single crystals (x = 0.044 and 0.051) down to 80 mK. For both samples, the residual linear term κ₀/T at zero field is negligible, which is a clear evidence for nodeless superconducting gap. Furthermore, the field dependence of κ₀/T manifests a multigap behavior. Lastly, these results demonstrate multiple nodeless superconducting gaps in ZrTe_3–x Se_x, which indicates conventional superconductivity despite of the existence of a CDW QCP.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC00112704
• OSTI ID: 1345739
• Report Number(s): BNL-113579-2017-JA; R&D Project: PM016; KC0201050
• Journal Information: Chinese Physics. B, Vol. 25, Issue 7; ISSN 1674-1056
• Publisher: IOP PublishingCopyright Statement
• Country of Publication: United States
• Language: English