Entanglement of indistinguishable particles as a probe for quantum phase transitions in the extended Hubbard model

TL;DR

This paper demonstrates that entanglement of particles effectively detects quantum phase transitions in the extended Hubbard model, distinguishing between first and second order transitions through entanglement behavior.

Contribution

It introduces the use of entanglement of particles as a tool to identify and analyze quantum phase transitions in the extended Hubbard model.

Findings

Discontinuities in entanglement indicate first order transitions.

Local minima in entanglement correspond to second order transitions.

Entanglement helps map the phase diagram, except for certain subtle phase boundaries.

Abstract

We investigate the quantum phase transitions of the extended Hubbard model at half-filling with periodic boundary conditions employing the entanglement of particles, as opposed to the more traditional entanglement of modes. Our results show that the entanglement has either discontinuities or local minima at the critical points. We associate the discontinuities to first order transitions, and the minima to second order ones. Thus we show that the entanglement of particles can be used to derive the phase diagram, except for the subtle transitions between the phases SDW-BOW, and the superconductor phases TS-SS.