Superconducting gap structure in ambient-pressure-grown $\mathrm{LaO_{0.5}F_{0.5}BiS_{2}}$

Autor: Zhang, Jian, Huang, K., Ding, Z. F., MacLaughlin, D. E., Bernal, O. O., Ho, P. -C., Tan, C., Liu, X., Yazici, D., Maple, M. B., Shu, Lei
Rok vydání: 2016
Předmět:
Zdroj: Phys. Rev. B, 94, 224502 (2016)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevB.94.224502
Popis: We have performed transverse-field muon spin relaxation (TF-$\mu$SR) measurements on ambient-pressure-grown polycrystalline $\mathrm{LaO_{0.5}F_{0.5}BiS_{2}}$. From these measurements, no signature of magnetic order is found down to 25 mK. The value of the magnetic penetration depth extrapolated to 0 K is 0.89 (5) $\mu$m. The temperature dependence of superconducting penetration depth is best described by either a multigap s + s-wave model with $\Delta_{1}$ = 0.947 (7) meV and $\Delta_{2}$ = 0.22 (4) meV or the ansiotropic s-wave model with $\Delta(0)$ = 0.776 meV and anisotropic gap amplitude ratio $\Delta_{min}/\Delta_{max}$ = 0.34. Comparisons with other potentially multigap $\mathrm{BiS_{2}}$-based superconductors are discussed. We find that these $\mathrm{BiS_{2}}$-based superconductors, including $\mathrm{Bi_{4}O_{4}S_3}$ and the high-pressure synthesized $\mathrm{LaO_{0.5}F_{0.5}BiS_{2}}$, generally conform to the Uemura relation.
Comment: 6 pages, 4 figures
Databáze: arXiv