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Extremely high upper critical field in BiCh₂-based (Ch: S and Se) layered superconductor LaO_0.5F_0.5BiS_2-xSe_x (x = 0.22 and 0.69).

ABSTRACT: Centrosymmetric compounds with local inversion symmetry breaking have tremendously interesting and intriguing physical properties. In this study, we focus on a BiCh₂-based (Ch: S, Se) layered superconductor, as a system with local inversion asymmetry, because spin polarisation based on the Rashba-Dresselhaus-type spin-orbit coupling has been observed in centrosymmetric BiCh₂-based LaOBiS₂ systems, while the BiCh₂ layer lacks local inversion symmetry. Herein, we report the existence of extremely high in-plane upper critical fields in the BiCh₂-based system LaO_0.5F_0.5BiS_2-xSe_x (x = 0.22 and 0.69). The superconducting states are not completely suppressed by the applied magnetic fields with strengths up to 55 T. Thus, we consider that the in-plane upper critical field is enhanced by the local inversion symmetry breaking and its layered structure. Our study will open a new pathway for the discovery of superconductors that exhibit a high upper critical field by focusing on the local inversion symmetry breaking.

SUBMITTER: Hoshi K

PROVIDER: S-EPMC8741910 | biostudies-literature |

REPOSITORIES: biostudies-literature

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