Broken time-reversal symmetry in superconducting Pr1-xCexPt4Ge12
Broken time-reversal symmetry in superconducting Pr1-xCexPt4Ge12
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超导 Pr1-xCexPt4Ge12 中破缺的时间反演对称性
DOI：
10.1103/physrevb.91.104523
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发表时间：
2015
影响因子：
3.7
通讯作者：
Shu Lei
中科院分区：
文献类型：
--
作者：
Zhang Jian;MacLaughlin D. E.;Hillier A. D.;Ding Z. F.;Huang K.;Maple M. B.;Shu Lei
本文报道了零场μ子自旋弛豫实验的结果，研究了Ce掺杂对超导状态下破缺时间反转对称性（TRS）的影响。在这些合金中，断裂的TRS是由低于超导转变温度的自发静态局部磁场开始的信号。我们发现，在接近不再观察到超导性的浓度时，它会线性下降。等结构合金系和等结构合金系均表现出TRS断裂的超导电性，且均与Pr浓度的降低成正比。这表明Pr-Pr位点间相互作用是导致TRS断裂的原因。这两个合金系列的不同之处在于，在所有La浓度下，La掺杂合金都是超导的，这表明Ce掺杂的断对抑制了超导性。在超导状态下，动态介子自旋弛豫速率有所下降。这可能是由于传导电子的柯林加弛豫，这种弛豫由于超导能隙的打开而减少。
We report results of zero-field muon spin relaxation experiments on the filled-skutterudite superconductors, 0.07, 0.1, and 0.2, to investigate the effect of Ce doping on broken time-reversal symmetry (TRS) in the superconducting state. In these alloys broken TRS is signaled by the onset of a spontaneous static local magnetic fieldbelow the superconducting transition temperature. We find thatdecreases linearly withandat, close to the concentration above which superconductivity is no longer observed. Theand isostructuralalloy series both exhibit superconductivity with broken TRS, and in both the decrease ofis proportional to the decrease of Pr concentration. This suggests that Pr-Pr intersite interactions are responsible for the broken TRS. The two alloy series differ in that the La-doped alloys are superconducting for all La concentrations, suggesting that inpair-breaking by Ce doping suppresses superconductivity. For allthe dynamic muon spin relaxation rate decreases somewhat in the superconducting state. This may be due to Korringa relaxation by conduction electrons, which is reduced by the opening of the superconducting energy gap.