Hole binding in two-dimensional t–J models realized with ultracold polar molecules

Characterize how holes bind in two-dimensional t–J models relevant to itinerant ultracold polar molecules in optical lattices, including the dipolar t–J⊥ model obtained without an electric field and the extended t–J–V–W model arising with tunneling and below unit filling; determine the binding mechanism and conditions as functions of interaction parameters and lattice geometry.

Background

The review discusses itinerant models for ultracold polar molecules in optical lattices, where allowing tunneling and using rotational states leads to variants of the t–J model (including dipolar interactions and extensions with density terms). While one-dimensional versions have predicted ground-state phases and correlation properties, the two-dimensional case remains numerically challenging. Understanding the nature of hole binding in these 2D models is highlighted as an important open question, directly relevant to condensed-matter analogs such as high-temperature superconductivity and to the capabilities of molecular quantum simulators.

The authors emphasize that the molecular platform enables tunable long-range dipole-dipole interactions and flexible Hamiltonian engineering, making it well-suited to tackle outstanding problems in 2D strongly correlated systems that are difficult for classical computation.