美国科罗拉多大学Jun Ye团队研究了具有可调偶极相互作用的广义t-J自旋动力学观测。2025年4月25日出版的《科学》杂志发表了这项成果。

长程和各向异性偶极相互作用深刻地改变了粒子在周期晶格势中跳跃的动力学。研究组报告了使用自旋编码在两个最低旋转态的超冷费米子分子系统实现了具有偶极相互作用的广义t-J模型。他们独立地调谐了偶极伊辛和自旋交换耦合以及分子运动，并研究了它们在相干自旋动力学中的相互作用。

使用拉姆齐光谱学，研究组观察并模拟了相互作用驱动的对比度衰减，该衰减强烈依赖于伊辛和自旋交换耦合之间的各向异性强度以及运动。这项研究为未来探索动态自旋动力学和量子磁性铺平了道路，这些动力学和量子磁学具有高度可调的分子平台，对现有的数值和分析方法具有挑战性。

附：英文原文

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

Author: Annette N. Carroll, Henrik Hirzler, Calder Miller, David Wellnitz, Sean R. Muleady, Junyu Lin, Krzysztof P. Zamarski, Reuben R. W. Wang, John L. Bohn, Ana Maria Rey, Jun Ye

Issue&Volume: 2025-04-25

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.

DOI: adq0911

Source: https://www.science.org/doi/10.1126/science.adq0911