Biorthogonal projected energies of a Gutzwiller similarity transformed Hamiltonian

TL;DR

This paper introduces a novel method combining biorthogonal orbital optimization, symmetry projection, and Gutzwiller similarity transformation to accurately compute energies in the Hubbard model, achieving high-quality results with mean-field scaling.

Contribution

It develops a new approach integrating biorthogonal transformations and Gutzwiller factors for improved energy calculations in strongly correlated systems.

Findings

Achieves energies comparable to coupled cluster methods.

Applicable to large 2D lattice systems.

Demonstrates scalability with mean-field computational cost.

Abstract

We present a method incorporating biorthogonal orbital-optimization, symmetry projection, and double-occupancy screening with a non-unitary similarity transformation generated by the Gutzwiller factor $ n_{i\uparrow}n_{i\downarrow}$, and apply it to the Hubbard model. Energies are calculated with mean-field computational scaling with high-quality results comparable to coupled cluster singles and doubles. This builds on previous work performing similarity transformations with more general, two-body Jastrow-style correlators. The theory is tested on two-dimensional lattices ranging from small systems into the thermodynamic limit and is compared to available reference data.