Fidelity susceptibilities in the one-dimensional extended Hubbard model

TL;DR

This paper uses density matrix renormalization group methods to analyze fidelity susceptibilities in 1D Hubbard and extended Hubbard models, revealing critical points and phase transitions.

Contribution

It demonstrates that fidelity susceptibility can detect quantum phase transitions and critical points in these models, including complex phase boundaries.

Findings

Fidelity susceptibility diverges near critical points in the Hubbard model.

It reveals multiple quantum phase transitions in the extended Hubbard model.

Fidelity susceptibility is extensive at critical points, indicating phase transitions.

Abstract

We investigated the fidelity susceptibility in the one-dimension (1D) Hubbard model and the extended Hubbard model at half-filling via the density matrix renormalization group. From the numerical results, we argue that in the 1D Hubbard model, the fidelity susceptibility shows a divergence at two points which is infinitesimally close to the critical point while it is always extensive exactly at the critical point. For the extended Hubbard model, we found that for a properly chosen driving parameter, the fidelity susceptibility is able to reveal the quantum phase transitions between the PS (phase separation)-superconducting, superconducting-CDW (charge-density wave), CDW-SDW(spin-density wave), SDW-PS, CDW-BOW (bond-order wave), and the BOW-SDW phases.