论文标题
间隙的扩展S波对称性与旋转轨道耦合在准二维超导体的低电子浓度状态下
Interplay between the extended s-wave symmetry of the gap and the spin-orbit coupling in the low-electron concentration regime of quasi-two-dimensional superconductors
论文作者
论文摘要
我们将真实空间配对的状态与$ \ mathbf {k} $ - 在Rashba型旋转轨道耦合和外部磁场的情况下的依赖性超导差距。我们表明，$扩展的$ $ s $ - $ wave $配对对称性是在低电子浓度制度中出现的最可能的情况。根据我们的研究，自旋轨道耦合引起的范霍夫奇异性可能会导致超导间隙，临界温度和临界磁场的显着增强。此外，自旋轨道耦合和外部磁场的综合效应导致库珀对的非零总动量，这是所谓的螺旋状态的特征。在这种情况下，由于c $ _4 $对称破坏，$ d $ - $ wave $和$ p $ - $ wave $ $ wave $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ - $ d $ - $ wave $出现，这大大改变了螺旋状态的特征。在与过渡金属氧化物界面的非常规超导特征以及最近报道的超电流二极管效应有关的实验数据的背景下进行了讨论。
We analyze the real-space paired state with the $\mathbf{k}$-dependent superconducting gap in the presence of Rashba type spin-orbit coupling and external magnetic field. We show that the $extended$ $s$-$wave$ pairing symmetry is the most probable scenario to appear in the low-electron concentration regime. According to our study, the van Hove singularity induced by the spin-orbit coupling may lead to a significant enhancement of the superconducting gap, critical temperature and critical magnetic field. Moreover, the combined effect of the spin-orbit coupling and the external magnetic field results in a non-zero total momentum of the Cooper pairs, which is a characteristic feature of the so-called helical state. In such situation, due to the C$_4$ symmetry breaking, a small $d$-$wave$ and $p$-$wave$ contributions to the pairing appear, which significantly change the character of the helical state. The obtained results are discussed in the context of the experimental data related with the unconventional superconducting features of the transition metal oxide interfaces as well as the recently reported supercurrent diode effect.
