论文标题
超导波动的发作温度在te-nealed fete $ _ {1-x} $ se $ _x $单晶：BCS-BEC交叉的证据
Onset Temperatures for Superconducting Fluctuations in Te-annealed FeTe$_{1-x}$Se$_x$ Single Crystals: Evidence for the BCS-BEC Crossover
论文作者
论文摘要
最近，超导体社区目睹了关于基于铁的超级导体（尤其是FESE和FESE $ _ {1-X} $ s $ _X $的辩论，都在Bardeen-Cooper-Shrieffer（BCS） - Bose-Inter-Interver（Bec）Condensation（BEC）跨境制度中。尽管如此，一个特定的系统，即fete $ _ {1-x} $ se $ _x $，由于不可避免的铁的过量筛选了其内在的超导性属性，因此在这方面对此进行了较少的研究。在此，通过测量TE降低的，高质量的fete $ _ {1-x} $ se $ _x $ _x $（$ x $ x $ x $ x $ x $ = 0.1、0.2、0.3、0.3、0.3和0.4），研究了超导波动的发作温度（$ t_ {scf} $）。结果显示这些晶体的$ T_ {SCF} $值非常高。特别是对于$ x $ = 0.4，$ t_ {scf} $达到约40 K，大于$ t_c $的2.7倍。这表明FETE $ _ {1-X} $ SE $ _X $ SYSTEM的超导性在BCS-BEC交叉制度范围内。
Recently, the superconductors' community has witnessed an unsettled debate regarding whether iron-based superconductors, in particular FeSe and FeSe$_{1-x}$S$_x$, are in the Bardeen-Cooper-Shrieffer (BCS) - Bose-Einstein condensation (BEC) crossover regime. Nonetheless, one particular system, FeTe$_{1-x}$Se$_x$, has been less investigated in this regard owing to the screening of its intrinsic superconducting properties by the inevitable iron excess. Herein, the onset temperatures for superconducting fluctuations ($T_{scf}$) are investigated by measuring the magnetoresistance (MR) of Te-annealed, high-quality FeTe$_{1-x}$Se$_x$ ($x$ = 0.1, 0.2, 0.3, and 0.4) single crystals. The results reveal very high $T_{scf}$ values for these crystals. Particularly for $x$ = 0.4, $T_{scf}$ reaches approximately 40 K, which is 2.7 times larger than $T_c$. This indicates that the superconductivity of the FeTe$_{1-x}$Se$_x$ system is well within the BCS-BEC crossover regime.
