近日，美国科罗拉多大学的Jun Ye&Calder Miller及其研究团队取得一项新进展。经过不懈努力，他们利用弗洛凯工程构建的极性分子XYZ自旋模型实现双轴扭曲。相关研究成果已于2024年9月11日在国际权威学术期刊《自然》上发表。

该研究团队利用弗洛凯工程实现了极性分子的新型量子多体系统。通过将自旋编码在超冷⁴⁰K⁸⁷Rb分子的两个最低转动态中，研究人员通过观察拉姆齐对比度动力学，对由弗洛凯微波脉冲序列调谐的XXZ自旋模型与由直流电场调谐的模型进行了相互验证。这一验证为实现静态场无法获取的哈密顿量奠定了基础。

特别是，研究人员观察到了由弗洛凯工程构建的XYZ模型在二维层中使用迁移分子所产生的双轴扭曲平均场动力学。未来，弗洛凯工程构建的哈密顿量有望为基于分子的精密测量产生纠缠态，或利用丰富的分子结构对多级系统进行量子模拟。

据悉，被限制在光晶格中的极性分子是一个多功能平台，可用于探索基于强远程偶极相互作用的自旋-运动动力学。通过微波和直流电场对伊辛相互作用和自旋交换相互作用的精确可调谐性，使得该分子系统特别适合于构建复杂的多体动力学。

附：英文原文

Title: Two-axis twisting using Floquet-engineered XYZ spin models with polar molecules

Author: Miller, Calder, Carroll, Annette N., Lin, Junyu, Hirzler, Henrik, Gao, Haoyang, Zhou, Hengyun, Lukin, Mikhail D., Ye, Jun

Issue&Volume: 2024-09-11

Abstract: Polar molecules confined in an optical lattice are a versatile platform to explore spin-motion dynamics based on strong, long-range dipolar interactions. The precise tunability of Ising and spin-exchange interactions with both microwave and d.c. electric fields makes the molecular system particularly suitable for engineering complex many-body dynamics. Here we used Floquet engineering to realize new quantum many-body systems of polar molecules. Using a spin encoded in the two lowest rotational states of ultracold ⁴⁰K⁸⁷Rb molecules, we mutually validated XXZ spin models tuned by a Floquet microwave pulse sequence against those tuned by a d.c. electric field through observations of Ramsey contrast dynamics. This validation sets the stage for the realization of Hamiltonians inaccessible with static fields. In particular, we observed two-axis twisting mean-field dynamics, generated by a Floquet-engineered XYZ model using itinerant molecules in two-dimensional layers. In the future, Floquet-engineered Hamiltonians could generate entangled states for molecule-based precision measurement9 or could take advantage of the rich molecular structure for quantum simulation of multi-level systems.

DOI: 10.1038/s41586-024-07883-2

Source: https://www.nature.com/articles/s41586-024-07883-2