Quantum Magnetism with Polar Alkali Dimers

TL;DR

This paper proposes using ultracold polar alkali dimers in optical lattices to realize a highly tunable long-range interacting model, enabling exploration of exotic quantum phases and strongly correlated phenomena.

Contribution

It introduces the t-J-V-W model with independently controllable long-range interactions using polar molecules and external fields, expanding the toolkit for quantum simulation.

Findings

Demonstrates control over interaction magnitudes and signs

Shows potential for simulating exotic quantum phases

Discusses robustness against experimental imperfections

Abstract

We show that dipolar interactions between ultracold polar alkali dimers in optical lattices can be used to realize a highly tunable generalization of the t-J model, which we refer to as the t-J-V-W model. The model features long-range spin-spin interactions J_z and J_perp of XXZ type, long-range density-density interaction V, and long-range density-spin interaction W, all of which can be controlled in both magnitude and sign independently of each other and of the tunneling t. The "spin" is encoded in the rotational degree of freedom of the molecules, while the interactions are controlled by applied static electric and continuous-wave microwave fields. Furthermore, we show that nuclear spins of the molecules can be used to implement an additional (orbital) degree of freedom that is coupled to the original rotational degree of freedom in a tunable way. The presented system is expected to exhibit exotic physics and to provide insights into strongly correlated phenomena in condensed matter systems. Realistic experimental imperfections are discussed.