Superconductivity with broken time-reversal symmetry in ion-irradiated Ba0.27K0.73Fe2As2 single crystals
Superconductivity with broken time-reversal symmetry in ion-irradiated Ba0.27K0.73Fe2As2 single crystals
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DOI：
10.1103/physrevb.95.214511
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发表时间：
2017-06-22
影响因子：
3.7
通讯作者：
Klauss, H. -H.
中科院分区：
文献类型：
--
作者：
Grinenko, V.;Materne, P.;Klauss, H. -H.
在过去的几年里，人们在理论和实验上做了大量的努力来寻找多带超导体中的时间反演对称性破缺态。特别地，从理论上提出，在Ba_（1-x）K-x Fe_2As_2系统中，在相图的窄区域中，在高掺杂水平下，可以存在s + is或s + id BTRS状态。在这里，我们报告的观察增强零场μ子自旋弛豫率低于超导转变温度的高品质的晶体样品与x接近0.73。这表明，在此掺杂水平下，超导体Ba_（1-x）K_xFe_2As_2中的时间反演对称性确实被破坏。
Over the past years a lot of theoretical and experimental effort has been made to find states with broken time-reversal symmetry (BTRS) in multiband superconductors. In particular, it was proposed theoretically that in the Ba1-x K-x Fe2As2 system either an s + is or an s + id BTRS state may exist at high doping levels in a narrow region of the phase diagram. Here we report the observation of an enhanced zero-field muon spin-relaxation rate below the superconducting transition temperature for a high quality crystalline sample with x approximate to 0.73. This indicates that indeed the time-reversal symmetry is broken in superconducting Ba1-x K-x Fe2As2 at this doping level.