近日，美国普渡大学Jonathan D. Hood及其研究团队取得一项新进展。经过不懈努力，他们提出自旋囚禁原子的光学冷却广义理论。相关研究成果已于2024年10月24日在国际知名学术期刊《物理评论A》上发表。

在这项工作中，该研究团队提出一种针对中性原子光镊中光学冷却机制的统一形式体系，涵盖了不同囚禁势下的可分辨与不可分辨边带冷却、偏振梯度冷却、灰模冷却、Λ型增强的灰模冷却以及拉曼边带冷却。研究人员进行了超精细能级的模拟，并展示了与简化自旋模型的良好一致性。

研究人员推导并讨论了每种冷却机制的基本极限，并提出了在光镊中实现基态冷却的新策略。这项研究结果为优化光镊中中性原子的冷却方案提供了宝贵见解，为最小化里德伯格门和分子门中的热退相干以及提高分子组装效率铺平了道路。

据悉，对于高保真成像、冷却以及分子组装而言，将原子冷却至光镊的基态正变得愈发重要。尽管针对自由空间中的冷却已开展了大量理论研究，但针对束缚态中冷却的研究却相对较少。

附：英文原文

Title: Generalized theory for optical cooling of a trapped atom with spin

Author: Saumitra S. Phatak, Karl N. Blodgett, David Peana, Meng Raymond Chen, Jonathan D. Hood

Issue&Volume: 2024/10/24

Abstract: Cooling atoms to the ground state of optical tweezers is becoming increasingly important for high-fidelity imaging, cooling, and molecular assembly. While extensive theoretical work has been conducted on cooling in free space, fewer studies have focused on cooling in bound states. In this work, we present a unified formalism for optical cooling mechanisms in neutral atom tweezers, including resolved and unresolved sideband cooling with different trapping potentials, polarization gradient cooling, gray molasses cooling, Λ-enhanced gray molasses cooling, and Raman sideband cooling. We perform simulations with hyperfine levels and demonstrate good agreement with a simplified spin model. We derive and discuss the fundamental limits of each cooling mechanism and propose new strategies for achieving ground state cooling in optical tweezers. Our findings provide valuable insights into optimizing cooling schemes for neutral atoms in optical tweezers, paving the way for minimizing thermal decoherence in Rydberg and molecular gates and improving efficiencies of molecular assembly.

DOI: 10.1103/PhysRevA.110.043116

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.110.043116