Pair Superfluidity of Three-Body Constrained Bosons in Two Dimensions

Understand

We examine the equilibrium properties of lattice bosons with attractive on-site interactions in the presence of a three-body hard-core constraint that stabilizes the system against collapse and gives rise to a dimer superfluid phase formed by virtual hopping processes of boson pairs.

• Employing quantum Monte Carlo simulations, the ground state phase diagram of this system on the square lattice is analyzed.
• In particular, we study the quantum phase transition between the atomic and dimer superfluid regime and analyze the nature of the superfluid-insulator transitions.
• Evidence is provided for the existence of a tricritical point along the saturation transition line, where the transition changes from being first-order to a continuous transition of the dilute bose gas of holes.