论文标题
具有自旋轨道耦合的二维系统中的多型增强超导性
Multifractally-enhanced superconductivity in two-dimensional systems with spin-orbit coupling
论文作者
论文摘要
已知Anderson定位和电子电子相互作用的相互作用会导致由于电子波函数的多纹理而增加超导性。在存在自旋轨道耦合的情况下，我们在二维系统中发展了多纹状体增强的超导状态的理论。使用Finkel'Stein非线性Sigma模型，我们得出了经过修改的USADEL和GAP方程，这些方程考虑了由混乱和相互作用的相互作用引起的重量化。多重相关性诱导超导光谱间隙的能量依赖性。在ISING和强旋转轨道耦合的情况下，我们确定了超导过渡温度和超导光谱间隙。在后一种情况下，超导光谱间隙的能量依赖性为凸，而在前一种情况下（以及在没有自旋轨道耦合的情况下），它是凹的。多重纹理不仅增强了过渡温度，而且以相同的方式增强了零温度下的光谱差距。我们还研究超导状态状态状态局部密度的介观波动。与正常金属的情况类似，自旋轨道耦合降低了波动的幅度。
The interplay of Anderson localization and electron-electron interactions is known to lead to enhancement of superconductivity due to multifractality of electron wave functions. We develop the theory of multifractally-enhanced superconducting states in two-dimensional systems in the presence of spin-orbit coupling. Using the Finkel'stein nonlinear sigma model, we derive the modified Usadel and gap equations that take into account renormalizations caused by the interplay of disorder and interactions. Multifractal correlations induce energy dependence of the superconducting spectral gap. We determine the superconducting transition temperature and the superconducting spectral gap in the case of Ising and strong spin orbit couplings. In the latter case the energy dependence of superconducting spectral gap is convex whereas in the former case (as well as in the absence of spin-orbit coupling) it is concave. Multifractality enhances not only the transition temperature but, in the same way, the spectral gap at zero temperature. Also we study mesoscopic fluctuations of the local density of states in the superconducting state. Similarly to the case of normal metal, spin-orbit coupling reduce the amplitude of fluctuations.
