Quantum information analysis of quantum phase transitions in a one-dimensional V1-V2 hard-core-boson model

TL;DR

This paper investigates quantum phase transitions in a one-dimensional V1-V2 hard-core-boson model using entanglement entropy and fidelity, revealing how these measures detect phase changes with numerical methods.

Contribution

It introduces a detailed analysis of entanglement entropy and fidelity susceptibility to identify multiple quantum phase transitions in a complex bosonic model.

Findings

Entanglement entropy derivatives detect all three phase transitions.

Fidelity susceptibility fails to identify the superfluid to bond-order transition in finite systems.

Numerical methods used include exact diagonalization and density matrix renormalization group.

Abstract

The entanglement entropy and quantum fidelity in a hard-core-boson model with nearest- and next-nearest-neighbor interactions are studied numerically. By using exact diagonalization and the density matrix renormalization group, the effects of interactions on entanglement entropy and fidelity susceptibility in the model are investigated. We focus our attention on looking for three quantum phase transitions. It is found that the first derivative of the entanglement entropy can indicate all of three phase transitions, while the fidelity susceptibility cannot predict the transition from superfluid to bond-order in a finite-size system.