Entanglement Properties of the One-Dimensional Dimerized Fermi-Hubbard Model

TL;DR

This paper investigates the entanglement characteristics of a one-dimensional dimerized Fermi-Hubbard model, revealing distinct insulating phases at specific fillings and analyzing their entanglement spectra to understand their underlying mechanisms.

Contribution

It introduces a matrix-product-state approach to distinguish between two insulating phases and a metallic phase in the model, highlighting their different entanglement properties.

Findings

Two insulating phases are distinct with different gap origins.

Entanglement spectra reveal differences between phases.

Scaling of entanglement entropy reflects phase characteristics.

Abstract

We study the entanglement properties of the one-dimensional dimerized Fermi-Hubbard model. Using a matrix-product-state approach, we compute the ground state and identify two insulating phases at 1/2- and 3/4-filling, along with a metallic phase, whose mechanisms can be characterized by their entanglement spectra. Our findings indicate that the two insulating phases are distinct, implying that the phase at 1/2-filling has a charge gap arising from the band gap, which is enhanced by repulsive interactions, while the phase at 3/4-filling exhibits a Mott gap resulting from particle interactions. This difference between the two insulating phases is reflected in the scaling properties of the half-chain entanglement entropy and the distribution of the entanglement spectrum.