Superconductor-insulator transition and energy localization

Article

关键词: QUANTUM PHASE-TRANSITIONS;    ANTI-FERROMAGNETIC CHAIN;    DIRTY SUPERCONDUCTORS;    ANDERSON LOCALIZATION;    DISORDERED-SYSTEMS;    CRITICAL-BEHAVIOR;    SPIN-GLASS;    BI2SR2CACU2O8+DELTA;    POLYMERS;    MODEL;   

DOI  :  10.1103/PhysRevB.82.184534

来源: SCIE

【 摘 要 】

We develop an analytical theory for generic disorder-driven quantum phase transitions. We apply this formalism to the superconductor-insulator transition and we briefly discuss the applications to the order-disorder transition in quantum magnets. The effective spin-1/2 models for these transitions are solved in the cavity approximation which becomes exact on a Bethe lattice with large branching number K >> 1 and weak dimensionless coupling g << 1. The characteristic feature of the low-temperature phase is a large self-formed inhomogeneity of the order-parameter distribution near the critical point K >= K-c(g), where the critical temperature T-c of the ordering transition vanishes. We find that the local probability distribution P(B) of the order parameter B has a long power-law tail in the region where B is much larger than its typical value B-0. Near the quantum-critical point, at K -> K-c(g), the typical value of the order parameter vanishes exponentially, B-0 proportional to e(-C/[K-Kc(g)]) while the spatial scale N-inh of the order parameter inhomogeneities diverges as [K-K-c(g)](-2). In the disordered regime, realized at K

【 授权许可】

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