A new self-consistent basis generation scheme for polaron and bipolaron systems

TL;DR

This paper introduces a novel self-consistent variational basis generation method for polaron and bipolaron systems, significantly reducing computational complexity while maintaining high accuracy, enabling studies of larger and higher-dimensional electron-phonon systems.

Contribution

A new self-consistent basis generation scheme based on exact diagonalization that efficiently reduces variational space size for electron-phonon systems.

Findings

Achieves highly accurate ground state energies and correlation functions.

Reduces variational space size by an order of magnitude or more.

Potentially applicable to larger and higher-dimensional systems.

Abstract

We have developed a new self-consistent scheme of generating variational basis based on the exactdiagonalization, which can be applied efficiently to various types of electron-phonon systems. This scheme is quite general and brings down the size of the variational space by an order of magnitude or even more in some cases to reproduce the most precise ground state energies and correlation functions available in the literature. This method has enormous potential for application to systems with more electrons or in higher dimensions, which are still beyond the reach of exact-diagonalization just because of the sheer size of their variational space needed to get reasonably convergent results.