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arXiv 1503.06540cond-mat.supr-concond-mat.mes-hall
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超导体-绝缘体转变:Phase diagram和磁电阻

Superconductor-insulator transitions: Phase diagram and magnetoresistance

I. S. Burmistrov, I. V. Gornyi, A. D. Mirlin

摘要:

探讨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,以及磁阻。分析基于非线性西格玛模型的重整化群。导出的RG方程适用于无序状态下的最低阶,但适用于粒子-空穴和库珀通道中的任意电子-电子相互作用强度。系统与保存和打破自旋旋转对称性被认为是,无论是与短程和长程(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-绝缘体的转变是由一个固定的点控制的电阻率$R_c$的量子电阻$R_q = h/ 4e^2$的顺序。当施加横向磁场时,我们发现在低于$T_c$的温度下,存在很强的非单调磁电阻。

英文摘要:

Influence of disorder-induced Anderson localization and of electron-electron interaction on superconductivity in two-dimensional systems is explored. We determine the superconducting transition temperature $T_c$, the temperature dependence of the resistivity, the phase diagram, as well as the magnetoresistance. The analysis is based on the renormalization group (RG) for a nonlinear sigma model. Derived RG equations are valid to the lowest order in disorder but for arbitrary electron-electron interaction strength in particle-hole and Cooper channels. Systems with preserved and broken spin-rotational symmetry are considered, both with short-range and with long-range (Coulomb) interaction. In the cases 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 $T_c$.

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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