近日，美国国家标准与技术研究所Dietrich Leibfried团队研究了混合物种晶体超精细阱离子中三脚架结构的电磁诱导透明冷却。2025年4月10日出版的《物理评论A》杂志发表了这项成果。

原子运动的冷却是原子物理学许多分支的重要工具，从基础物理探索到量子信息和传感。对于捕获离子，电磁诱导透明（EIT）冷却技术因其相对速度快、激光功率要求低和冷却带宽宽而受到关注。然而，在以冷却为主题的离子具有超精细结构以实现长相干时间的应用中，很难找到一个封闭的三能级系统来执行标准的EIT冷却。

通过增加一个额外的激光频率，研究组成功地在²⁵Mg⁺上进行了EIT冷却；该方法可应用于任何具有非零核自旋的离子。此外，研究组同时对混合晶体的所有轴向模式通过²⁵Mg⁺离子进行EIT冷却 ⁹Be⁺-²⁵Mg⁺和 ⁹Be⁺-²⁵Mg⁺-⁹Be⁺。这证明了EIT冷却在架构中的可行性，其中激光冷却的物种可以承载高保真超精细量子位。

附：英文原文

Title: Electromagnetically-induced-transparency cooling with a tripod structure in a hyperfine trapped ion with mixed-species crystals

Author: Jenny J. Wu, Pan-Yu Hou, Stephen D. Erickson, Adam D. Brandt, Yong Wan, Giorgio Zarantonello, Daniel C. Cole, Andrew C. Wilson, Daniel H. Slichter, Dietrich Leibfried

Issue&Volume: 2025/04/10

Abstract: Cooling of atomic motion is a crucial tool for many branches of atomic physics, ranging from fundamental physics explorations to quantum information and sensing. For trapped ions, electromagnetically-induced-transparency (EIT) cooling has received attention for the relative speed, low laser power requirements, and broad cooling bandwidth of the technique. However, in applications where the ion used for cooling has hyperfine structure to enable long coherence times, it is difficult to find a closed three-level system in which to perform standard EIT cooling. Here, we demonstrate successful EIT cooling on  25 Mg +  by the addition of an extra laser frequency; this method can be applied to any ion with nonzero nuclear spin. Furthermore, we simultaneously EIT cool all axial modes in mixed-species crystals  9 Be + 25 Mg +  and  9 Be + 25 Mg + 9 Be+ through the 25 Mg + ion. This demonstrates the viability of EIT cooling in architectures where the laser-cooled species can host high-fidelity hyperfine qubits.

DOI: 10.1103/PhysRevA.111.043109

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.043109