Unitary limit and quantum interference effect in disordered two-dimensional crystals with nearly half-filled bands

Abstract

Based on the self-consistent $T$-matrix approximation, the quantum interference (QI) effect is studied with the diagrammatic technique in weakly-disordered two-dimensional crystals with nearly half-filled bands. In addition to the usual 0-mode cooperon and diffuson, there exist $\pi$-mode cooperon and diffuson in the unitary limit due to the particle-hole symmetry. The diffusive $\pi$-modes are gapped by the deviation from the exactly-nested Fermi surface. The conductivity diagrams with the gapped $\pi$-mode cooperon or diffuson are found to give rise to unconventional features of the QI effect. Besides the inelastic scattering, the thermal fluctuation is shown to be also an important dephasing mechanism in the QI processes related with the diffusive $\pi$-modes. In the proximity of the nesting case, a power-law anti-localization effect appears due to the $\pi$-mode diffuson. For large deviation from the nested Fermi surface, this anti-localization effect is suppressed, and the conductivity remains to have the usual logarithmic weak-localization correction contributed by the 0-mode cooperon. As a result, the dc conductivity in the unitary limit becomes a non-monotonic function of the temperature or the sample size, which is quite different from the prediction of the usual weak-localization theory.

21 pages, 4 figures

References in corpus (15)

• Riemannian symmetric superspaces and their origin in random matrix theory
• The spectrum of the QCD Dirac operator and chiral random matrix theory: the threefold way
• Interaction corrections at intermediate temperatures: I. Longitudinal conductivity and kinetic equation
• Electron--electron Interactions in Disordered Metals: Keldysh Formalism
• gl(N|N) Super-Current Algebras for Disordered Dirac Fermions in Two Dimensions
• The two-dimensional Anderson model of localization with random hopping
• Particle-Hole Symmetry and the Effect of Disorder on the Mott-Hubbard Insulator
• Anderson localization in bipartite lattices
• Nesting symmetries and diffusion in disordered d-wave superconductors
• Power-law Localization in 2D, 3D with Off-diagonal Disorder
• Metal-insulator transition in two-dimensional disordered systems with power-law transfer terms
• Interacting random Dirac fermions in superconducting cuprates
• Density of States of Disordered Two-Dimensional Crystals with Half-Filled Band
• Effect of Substitutional Impurities on the Electronic States and Conductivity of Crystals with Half-filled Band
• Comment on ``Density of States of Disordered Two-Dimensional Crystals with Half-Filled Band''