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arXiv 1908.09476cond-mat.supr-concond-mat.str-el
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非常规$s$波超导态对无序的鲁棒性

Robustness of unconventional $s$-wave superconducting states against disorder

D. C. Cavanagh, P. M. R. Brydon

摘要:

我们研究了费米子具有四个内部自由度的多带系统中超导性对无序的鲁棒性。这允许非常规的$s$ -波配对状态,其可以在晶体对称性下非平凡地变换。使用自洽玻恩近似,我们开发了一个一般的理论上的临界温度的杂质的影响,并发现,这些新的$s$波通道的存在显着修改单带理论的结论。我们将我们的理论应用到两个候选的拓扑超导体,YPtBi和Cu $_x$ Bi $_2$ Se $_3$,并表明,新的$s$波状态显示出增强的弹性对无序,扩展到动量依赖的配对状态具有相同的晶体对称性。$s$波状态的鲁棒性可以根据它们的超导适应性来量化,这可以很容易地对模型系统进行评估。

英文摘要:

We investigate the robustness against disorder of superconductivity in multiband systems where the fermions have four internal degrees of freedom. This permits unconventional $s$-wave pairing states, which may transform nontrivially under crystal symmetries. Using the self-consistent Born approximation, we develop a general theory for the effect of impurities on the critical temperature, and find that the presence of these novel $s$-wave channels significantly modifies the conclusions of single-band theories. We apply our theory to two candidate topological superconductors, YPtBi and Cu$_x$Bi$_2$Se$_3$, and show that the novel $s$-wave states display an enhanced resilience against disorder, which extends to momentum-dependent pairing states with the same crystal symmetry. The robustness of the $s$-wave states can be quantified in terms of their superconducting fitness, which can be readily evaluated for model systems.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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