Observation of generalized t-J spin dynamics with tunable dipolar interactions

TL;DR

This paper demonstrates the realization of a generalized t-J model with tunable dipolar interactions in ultracold molecules, revealing how anisotropic long-range interactions influence spin dynamics and coherence.

Contribution

It introduces a highly tunable molecular platform to study generalized t-J models with dipolar interactions, enabling exploration of complex quantum magnetic phenomena.

Findings

Interaction-driven contrast decay depends on anisotropy and motion.

Tunable dipolar Ising and spin-exchange couplings were independently controlled.

The system enables future studies of kinetic spin dynamics and quantum magnetism.

Abstract

Long-range and anisotropic dipolar interactions profoundly modify the dynamics of particles hopping in a periodic lattice potential. We report the realization of a generalized t-J model with dipolar interactions using a system of ultracold fermionic molecules with spin encoded in the two lowest rotational states. We independently tuned the dipolar Ising and spin-exchange couplings and the molecular motion and studied their interplay on coherent spin dynamics. Using Ramsey spectroscopy, we observed and modeled interaction-driven contrast decay that depends strongly both on the strength of the anisotropy between Ising and spin-exchange couplings and on motion. This study paves the way for future exploration of kinetic spin dynamics and quantum magnetism with highly tunable molecular platforms in regimes that are challenging for existing numerical and analytical methods.