Supersolid phases in the extended boson hubbard model

TL;DR

This study maps the phase diagram of a 2D extended hardcore boson Hubbard model, revealing novel supersolid phases at specific fillings and a first-order transition between different supersolids.

Contribution

It uncovers the existence of striped and quarter-filled supersolids due to competing interactions, expanding understanding of quantum phases in extended Hubbard models.

Findings

Identification of striped supersolid and quarter-filled supersolid phases.

Observation of a first-order quantum phase transition between different supersolids.

Detailed phase diagram including solid, superfluid, and multiple supersolid phases.

Abstract

We present a comprehensive numerical study on the ground state phase diagram of the two-dimensional hardcore boson extended Hubbard model with nearest ($V_1$) and next nearest neighbor ($V_2$) repulsions. In addition to the quantum solid and superfluid phases, we report the existence of striped supersolid and three-quarter (quarter) filled supersolid at commensurate density $\rho=0.75$ (0.25) due to the interplay of $V_1$ and $V_2$ interactions. The nature of three-quarter filled supersolid and the associated quantum solid will be discussed. Quantum phase transition between the two supersolids of different symmetries is observed and is clearly of first order.