Superconductor-insulator transitions: Phase diagram and magnetoresistance
Superconductor-insulator transitions: Phase diagram and magnetoresistance
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DOI：
10.1103/physrevb.92.014506
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发表时间：
2015-07-13
影响因子：
3.7
通讯作者：
Mirlin, A. D.
中科院分区：
文献类型：
--
作者：
Burmistrov, I. S.;Gornyi, I. V.;Mirlin, A. D.
讨论了二维体系中无序诱导的安德森局域化和电子-电子相互作用对超导电性的影响。我们确定了超导转变温度T-c，电阻率的温度依赖性，相图，和磁阻。分析是基于非线性sigma模型的重整化群（RG）。导出的RG方程对无序状态下的最低阶有效，但对粒子-空穴和库珀沟道中任意的电子-电子相互作用强度都有效。系统与保存和打破自旋旋转对称性被认为是，与短程和长程（库仑）相互作用。在短程相互作用的情况下，我们确定的参数区域的超导电性增强的本地化效应。我们的RG分析表明，超导体-绝缘体转变是由一个固定点控制的，其电阻率R-c的数量级为量子电阻R-q = h/4 e（2）。当外加横向磁场时，在低于Tc的温度下，我们发现了很强的非单调磁电阻效应。
The influence of the disorder-induced Anderson localization and electron-electron interaction on the superconductivity in two-dimensional systems is explored. We determine the superconducting transition temperature T-c, the temperature dependence of the resistivity, the phase diagram, and the magnetoresistance. The analysis is based on the renormalization group (RG) for a nonlinear sigma model. The derived RG equations are valid to the lowest order in disorder but for an arbitrary electron-electron interaction strength in a particle-hole and the Cooper channels. Systems with preserved and broken spin-rotational symmetry are considered, with both short-range and long-range (Coulomb) interactions. In the case of short-range interaction, we identify parameter regions where the superconductivity is enhanced by localization effects. Our RG analysis indicates that the superconductor-insulator transition is controlled by a fixed point with a resistivity R-c of the order of the quantum resistance R-q = h/4e(2). When a transverse magnetic field is applied, we find a strong nonmonotonous magnetoresistance for temperatures below T-c.