Quantum critical magnetotransport at a continuous metal-insulator transition

Article

关键词: DISORDERED ELECTRONIC SYSTEMS;    SCALING THEORY;    HALL;   

DOI  :  10.1103/PhysRevB.96.155113

来源: SCIE

【 摘 要 】

In contrast to the seminal weak localization prediction of a noncritical Hall constant (R-H) at the Anderson metal-insulator transition (MIT), R-H in quite a few real disordered systems exhibits both a strong T dependence and critical scaling near their MIT. Here we investigate these issues in detail within a nonperturbative strong localization regime using cluster-dynamical mean-field theory (CDMFT). We uncover (i) clear and unconventional quantum-critical scaling of the Gell-Mann law, or gamma function for magnetotransport, finding that gamma(g(xy)) = d[log(g(xy))]/d[log(T)] similar or equal to log(g(xy)) over a wide range spanning the continuous MIT, very similar to that seen for the longitudinal conductivity, and (ii) strongly T dependent and clear quantum critical scaling in both transverse conductivity and R-H at the MIT. We show that these surprising results are in comprehensive and very good accord with signatures of a novel Mott-like localization in NbN near the MIT, providing substantial support for our strong localization view.

【 授权许可】

Free