Benchmarks and results of the two-band Hubbard model from the Gutzwiller conjugate gradient minimization theory

TL;DR

This paper introduces a Gutzwiller conjugate gradient minimization method for the one-dimensional two-band Hubbard model, achieving accurate ground-state properties and phase diagrams with significantly reduced computational effort.

Contribution

The paper presents a novel, efficient Gutzwiller conjugate gradient approach with rotational invariance for the two-band Hubbard model, improving accuracy and computational speed.

Findings

Method achieves results in good agreement with DMRG

Speedup of 300 times due to rotational invariance

Successfully reproduces the phase diagram of the model

Abstract

Ground-state properties, such as energies and double occupancies, of a one-dimensional two-band Hubbard model are calculated using a first principles Gutzwiller conjugate gradient minimization theory. The favorable agreement with the results from the density matrix renormalization group theory demonstrates the accuracy of our method. A rotationally invariant approach is further incorporated into the method to greatly reduce the computational complexity with a speedup of 300 times. Moreover, we investigate the Mott transition between a metal and a Mott insulator by evaluating the charge gap. With greatly reduced computational effort, our method reproduces the phase diagram in reasonable agreement with the density matrix renormalization group theory.