Renormalization group for Anderson localization on high-dimensional lattices.

Altshuler, Boris L; Kravtsov, Vladimir E; Scardicchio, Antonello; Sierant, Piotr; Vanoni, Carlo · Proc Natl Acad Sci U S A · 2025

basic_science · Level V

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Abstract

We discuss the dependence of the critical properties of the Anderson model on the dimension <i>d</i> in the language of <i>β</i>-function and renormalization group recently introduced in Vanoni et al. [C. Vanoni <i>et al.</i>, <i>Proc. Natl. Acad. Sci. U.S.A.</i> <b>121</b>, e2401955121 (2024)] in the context of Anderson transition on random regular graphs. We show how in the delocalized region, including the transition point, the one-parameter scaling part of the <i>β</i>-function for the fractal dimension [Formula: see text] evolves smoothly from its [Formula: see text] form, in which [Formula: see text], to its [Formula: see text] form, which is represented by the random regular graph (RRG) result. We show how the [Formula: see text] expansion and the [Formula: see text] expansion around the RRG result can be reconciled and how the initial part of a renormalization group trajectory governed by the irrelevant exponent <i>y</i> depends on dimensionality. We also show how the irrelevant exponent emerges out of the high-gradient terms of expansion in the nonlinear sigma model and put forward a conjecture about a lower bound for the fractal dimension. The framework introduced here may serve as a basis for investigations of disordered many-body systems and of more general nonequilibrium quantum systems.