Phase separation and pairing regimes in the one-dimensional asymmetric Hubbard model

TL;DR

This paper investigates the phase diagram of the one-dimensional asymmetric Hubbard model, revealing how pairing and charge-density wave regimes evolve with asymmetry and interaction strength through numerical and analytical methods.

Contribution

It provides new insights into the phase transitions and regimes in the asymmetric Hubbard model using combined numerical and analytical approaches.

Findings

Transition from pairing to charge-density waves with increasing asymmetry

Identification of phase separation onset in both strong and weak coupling regimes

Numerical and analytical methods complement each other in mapping phase diagram

Abstract

We address some open questions regarding the phase diagram of the one-dimensional Hubbard model with asymmetric hopping coefficients and balanced species. In the attractive regime we present a numerical study of the passage from on-site pairing dominant correlations at small asymmetries to charge-density waves in the region with markedly different hopping coefficients. In the repulsive regime we exploit two analytical treatments in the strong- and weak-coupling regimes in order to locate the onset of phase separation at small and large asymmetries respectively.