论文标题
$^{77} $ se nmr探测的FESE中高度自旋偏振电子的超导性
Superconductivity of highly spin-polarized electrons in FeSe probed by $^{77}$Se NMR
论文作者
论文摘要
许多最近的实验表明，铁核酸化的FESE提供了长期追求的可能性，可以在弱耦合的bardeen-cooper--cooper--schrieffer（BCS）配对与强烈耦合的Bose-bose-indeinstein Concemation（Becy）之间（becy）（贝斯）（becy）。我们报告了FESE的$^{77} $ SE核磁共振实验，该实验的重点是沿着$ C $轴施加的强磁场的超导相，报告了具有较大自旋极化的独特状态。我们将这种高场状态确定为散装超导，并具有低能量自旋波动的高空间均匀性。此外，我们发现尽管存在明显的自旋波动，但在接近超导状态的温度下，静态自旋敏感性变得异常小。综上所述，我们的结果清楚地表明，FESE确实具有在BCS-BEC跨界方面具有高度自旋极化的费米液体的异常场诱导的超导状态。
A number of recent experiments indicate that the iron-chalcogenide FeSe provides the long-sought possibility to study bulk superconductivity in the cross-over regime between the weakly coupled Bardeen--Cooper--Schrieffer (BCS) pairing and the strongly coupled Bose--Einstein condensation (BEC). We report on $^{77}$Se nuclear magnetic resonance experiments of FeSe, focused on the superconducting phase for strong magnetic fields applied along the $c$ axis, where a distinct state with large spin polarization was reported. We determine this high-field state as bulk superconducting with high spatial homogeneity of the low-energy spin fluctuations. Further, we find that the static spin susceptibility becomes unusually small at temperatures approaching the superconducting state, despite the presence of pronounced spin fluctuations. Taken together, our results clearly indicate that FeSe indeed features an unusual field-induced superconducting state of a highly spin-polarized Fermi liquid in the BCS-BEC crossover regime.
