Superconductor-insulator transitions: Phase diagram and magnetoresistance

Article

关键词: HIGH-TEMPERATURE SUPERCONDUCTIVITY;    ANDERSON LOCALIZATION;    ANOMALOUS DIMENSIONS;    THIN-FILM;    FLUCTUATION;    RESISTANCE;    DIFFUSION;    ENERGY;    CONDUCTIVITY;    SUPPRESSION;   

DOI  :  10.1103/PhysRevB.92.014506

来源: SCIE

【 摘 要 】

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.

【 授权许可】

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