Quantum critical magneto-transport at a continuous metal-insulator transition

Abstract

In contrast to the seminal weak localization prediction of a non-critical 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 non-perturbative "strong localization" regime using cluster-dynamical mean field theory (CDMFT). We uncover $(i)$ clear and unconventional quantum-critical scaling of the $\gamma$-function, finding that $\gamma (g_{xy})\simeq$ log$(g_{xy})$ over a wide range spanning the continuous MIT, very similar to that seen for the longitudinal conductivity, $(ii)$ strongly $T$-dependent and clear quantum critical scaling in both transverse conductivity and $R_H$ at the MIT. We find that these surprising results are in comprehensive and very good accord with signatures of a novel kind of localization in disordered NbN near the MIT, providing substantial support for our "strong" localization view.

6 pages, 8 figures

References in corpus (5)

• Optical properties of correlated materials -- Generalized Peierls approach and its application to VO2
• Optical Conductivity of the t-J model within Cluster Dynamical Mean Field Theory
• Temperature dependence of resistivity and Hall-coefficient in a strongly disordered metal: NbN
• Quantum critical transport at a continuous metal-insulator transition
• Real-space cluster dynamical mean-field approach to the Falicov-Kimball model: An alloy-analogy approach

Cited by in corpus (7)

• Mott quantum criticality in the one-band Hubbard model: Dynamical mean-field theory, power-law spectra, and scaling
• Extended Falicov-Kimball model: Exact solution for finite temperatures
• Extended Falicov-Kimball model: exact solution for the ground state
• Universal dielectric response across a continuous metal-insulator transition
• Robust pseudogap across the magnetic field driven superconductor to insulator-like transition in strongly disordered NbN films
• Universal Mott quantum criticality in a modified periodic Anderson model
• Quantum critical scaling of the conductivity tensor at the metal-insulator transition in Nb${}_{1-x}$Ti${}_x$N