Anisotropic upper critical magnetic fields in Rb₂Cr₃As₃ superconductor

Journal Article · Wed Sep 13 00:00:00 EDT 2017 · Journal of Physics. Condensed Matter

DOI:https://doi.org/10.1088/1361-648X/aa84eb· OSTI ID:1427518

Tang, Zhang -Tu ^[1]; Liu, Yi ^[1]; Bao, Jin-Ke ^[2]; Xi, Chuan -Ying ^[3]; Pi, Li ^[4]; Cao, Guang -Han ^[5]

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1. Zhejiang Univ., Hangzhou (People's Republic of China)
2. Zhejiang Univ., Hangzhou (People's Republic of China); Argonne National Lab. (ANL), Argonne, IL (United States)
3. Chinese Academy of Sciences, Hefei (People's Republic of China)
4. Chinese Academy of Sciences, Hefei (People's Republic of China); Univ. of Science and Technology of China, Hefei (People's Republic of China); Collaborative Innovation Centre of Advanced Microstructures, Nanjing (People's Republic of China)
5. Zhejiang Univ., Hangzhou (People's Republic of China); Collaborative Innovation Centre of Advanced Microstructures, Nanjing (People's Republic of China)

Rb₂Cr₃As₃ is a structurally one-dimensional superconductor containing Cr₃As₃ chains with a superconducting transition temperature of $$T_{\rm c}= 4.8$$ K. Here we report the electrical resistance measurements for Rb₂Cr₃As₃ single crystals, under magnetic fields up to 29.5 T and at temperatures down to 0.36 K, from which the upper critical fields, $$H_{{\rm c2}}(T)$$ , can be obtained in a broad temperature range. For field parallel to the Cr₃As₃ chains, $$H_{{\rm c2}}^{\Vert }(T)$$ is paramagnetically limited with an initial slope of $$\mu_{0}$$ d$$H_{{\rm c2}}^{\Vert }$$ /d$$T\vert _{T_{{\rm c}}}=-16$$ T $${\rm K}^{-1}$$ and a zero-temperature upper critical field of $$\mu_{0}H_{{\rm c2}}^{\Vert }(0)= 17.5$$ T. For field perpendicular to the Cr₃As₃ chains, however, $$H_{{\rm c2}}^{\bot}(T)$$ is only limited by orbital pair-breaking effect with $$\mu_{0}$$ d$$H_{{\rm c2}}^{\perp}$$ /d$$T\vert _{T_{{\rm c}}}=-3$$ T $${\rm K}^{-1}$$ . As a consequence, the anisotropy $$\gamma_{H}=H_{{\rm c2}}^{\Vert }/H_{{\rm c2}}^{\bot}$$ decreases sharply near T c and reverses below 2 K. Furthermore, the low-temperature $$H_{{\rm c2}}^{\bot}(T)$$ down to 0.075 $$T_{{\rm c}}$$ remains to increase linearly up to over three times the Pauli paramagnetic limit, which strongly suggests dominant spin-triplet superconductivity in Rb₂Cr₃As₃.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: National Science Foundation of China; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1427518
• Journal Information: Journal of Physics. Condensed Matter, Journal Name: Journal of Physics. Condensed Matter Journal Issue: 42 Vol. 29; ISSN 0953-8984
• Publisher: IOP Publishing
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
Cr-based superconductors
unconventional superconductivity
upper critical fields