Ground State Properties of the One-Dimensional Unconstrained Pseudo-Anyon Hubbard Model

TL;DR

This paper investigates the ground state properties of the one-dimensional pseudo-anyon Hubbard model, revealing exotic phases, phase transitions, and the effects of constraints and finite statistical angles on superfluidity.

Contribution

It provides a detailed analysis of the model's phases, including the first observation of a two-component partially paired phase without constraints and effects of induced hardcore constraints.

Findings

First order transition between superfluid phases

Existence of a two-component partially paired phase

Unconventional superfluid peaked at finite momentum

Abstract

We study the (pseudo-) anyon Hubbard model on a one-dimensional lattice without the presence of a three-body hardcore constraint. In particular, for the pseudo-fermion limit of a large statistical angle $\theta\approx\pi$, we observe a wealth of exotic properties including {a first order transition} between different superfluid phases and a {two-component} partially paired phase for large fillings without need of an additional three-body hardcore constraint.In this limit, we analyze the effect of an induced hardcore constraint, which leads to the stabilization of superfluid {ground states} for vanishing or even small attractive on-site interactions. For finite statistical angles, we study the unconventional broken-symmetry superfluid peaked at a finite momentum, resulting in an interesting beat phenomenon of single particle correlation functions.We show how some features of various ground state phases, including an analog of the partially paired phase in the pseudo-fermion limit, may be reproduced in a naive mean field frame.