Affordable Access

Publisher Website

Metal-insulator transition from combined disorder and interaction effects in Hubbard-like electronic lattice models with random hopping

Published Article
Publication Date
Submission Date
DOI: 10.1103/PhysRevB.77.165108
External links


We uncover a disorder-driven instability in the diffusive Fermi liquid phase of a class of many-fermion systems, indicative of a metal-insulator transition of first order type, which arises solely from the competition between quenched disorder and interparticle interactions. Our result is expected to be relevant for sufficiently strong disorder in d = 3 spatial dimensions. Specifically, we study a class of half-filled, Hubbard-like models for spinless fermions with (complex) random hopping and short-ranged interactions on bipartite lattices, in d > 1. In a given realization, the hopping disorder breaks time reversal invariance, but preserves the special ``nesting'' symmetry responsible for the charge density wave instability of the ballistic Fermi liquid. This disorder may arise, e.g., from the application of a random magnetic field to the otherwise clean model. We derive a low energy effective field theory description for this class of disordered, interacting fermion systems, which takes the form of a Finkel'stein non-linear sigma model [A. M. Finkel'stein, Zh. Eksp. Teor. Fiz. 84, 168 (1983), Sov. Phys. JETP 57, 97 (1983)]. We analyze the Finkel'stein sigma model using a perturbative, one-loop renormalization group analysis controlled via an epsilon-expansion in d = 2 + epsilon dimensions. We find that, in d = 2 dimensions, the interactions destabilize the conducting phase known to exist in the disordered, non-interacting system. The metal-insulator transition that we identify in d > 2 dimensions occurs for disorder strengths of order epsilon, and is therefore perturbatively accessible for epsilon << 1. We emphasize that the disordered system has no localized phase in the absence of interactions, so that a localized phase, and the transition into it, can only appear due to the presence of the interactions.

There are no comments yet on this publication. Be the first to share your thoughts.


Seen <100 times