Gutzwiller Renormalization Group

TL;DR

The paper introduces the Gutzwiller renormalization group (GRG), a variational method for accurately computing the ground state of Anderson impurity models, leveraging low-entanglement properties and Gutzwiller wavefunctions.

Contribution

It presents a novel variational scheme that efficiently captures the ground state of AIM with high precision, potentially surpassing existing methods.

Findings

Validated by benchmark calculations on single-band AIM

Demonstrates the ground state has a simple structure with few parameters

Suggests applicability to complex and nonequilibrium systems

Abstract

We develop a variational scheme called "Gutzwiller renormalization group" (GRG), which enables us to calculate the ground state of Anderson impurity models (AIM) with arbitrary numerical precision. Our method can exploit the low-entanglement property of the ground state in combination with the framework of the Gutzwiller wavefunction, and suggests that the ground state of the AIM has a very simple structure, which can be represented very accurately in terms of a surprisingly small number of variational parameters. We perform benchmark calculations of the single-band AIM that validate our theory and indicate that the GRG might enable us to study complex systems beyond the reach of the other methods presently available and pave the way to interesting generalizations, e.g., to nonequilibrium transport in nanostructures.