论文标题
在基于BIS2的分层超导体中，由结构对称性破坏驱动的可能的配对机制切换
Possible pairing mechanism switching driven by structural symmetry breaking in BiS2-based layered superconductors
论文作者
论文摘要
同位素对超导转变温度（TC）的研究是检查电子 - phonon相互作用是否对于配对机制必不可少的有用方法之一。基于BICH2的分层（CH：S，SE）超导体家族是非常规超导体的候选者，因为以前在LA（O，F）Bisse和BI4O4S3中观察到非常规同位素效应。在这项研究中，我们研究了（SR，LA）FBIS2的高压阶段中32S和34S的同位素效应，该阶段具有单斜晶体结构，在高压下具有10 K的TC较高的TC，并且在TC中观察到的常规型同位素移位。在（SR，LA）FBIS2的单斜相阶段中的常规类型同位素效应与具有四方结构的LA（O，F）Bisse和Bi4O4S3中观察到的非常规同位素效应不同。获得的结果表明，基于BICH2的超导体的配对机制可以通过压力效应引起的超导层的结构对称性变化来切换。
Investigation of isotope effects on superconducting transition temperature (Tc) is one of the useful methods to examine whether electron-phonon interaction is essential for pairing mechanisms. The layered BiCh2-based (Ch: S, Se) superconductor family is a candidate for unconventional superconductors, because unconventional isotope effects have previously been observed in La(O,F)BiSSe and Bi4O4S3. In this study, we investigated the isotope effects of 32S and 34S in the high-pressure phase of (Sr,La)FBiS2, which has a monoclinic crystal structure and a higher Tc of 10 K under high pressures, and observed conventional-type isotope shifts in Tc. The conventional-type isotope effects in the monoclinic phase of (Sr,La)FBiS2 are different from the unconventional isotope effects observed in La(O,F)BiSSe and Bi4O4S3, which have a tetragonal structure. The obtained results suggest that the pairing mechanisms of BiCh2-based superconductors could be switched by a structural-symmetry change in the superconducting layers induced by pressure effects.
