超冷钠铯极性分子的相干制备与量子态操控

Production of ultracold dense polar molecules at ground state is a cutting-edge issue in ultracold physics research field. It is of great significance for the research on precision measurements, quantum informatrion process,quantum simulation and for the exploration of many-body physics problems.The tight cross-connection between the coherent production and manipulation of ultracold polar molecules as well as quantum information processing has endowed the atomic and molecular physics with brand new research contents and scientific significances. This project based on the sub-micro Kelvin ultracold sodium and cesium atoms in an optical dipole trap, proposes the broadband optical pumping and stimulated Raman Photoassociation scheme. By coherently manipulating various optical fields utilizing the femtosecond optical frequency comb, dense ultracold sodium cesium polar molecules at low-lying ro-vibraitonal levels of ground state are coherently produced. We develop the researches on the physical mechnisms and the dynamical behaviors of the interation between the ground state polar molecules ensemble and the multiple optical fields during the population transferring process, based on which, the system is optimized to realize the aim of rapid and efficient coherent control of population transferring between the low-lying ro-vibrational levels in the ultracold ground state molecules.This project will provide the ideas as well as lay the foundation for exploration of quantum information processing researches based on the ultracold polar molecules system.

密集的基态超冷极性分子的制备是超冷物理研究领域的前沿热点问题，对于研究精密测量，量子信息处理，量子模拟以及探索多体物理问题等具有重要的意义。超冷极性分子的相干制备和操控与量子信息处理的紧密交叉结合为原子分子物理赋予了全新的研究内容与科学意义。本项目基于光学偶极阱俘获的亚微开密集超冷钠铯原子样品，提出宽带光学泵浦和受激拉曼光缔合有机结合的方案，利用飞秒光学频率梳进行多个光场的相干操控，相干制备密集的低振转基态超冷钠铯极性分子。研究低振转基态极性分子系综在布居转移过程中与多光场相互作用的物理机制与动力学行为，进而优化系统实现分子在基态低振转能级布居转移的高效和快速的相干操控，为探索超冷极性分子系统作为载体的量子信息处理的提供思路并奠定基础。

超冷极性分子量子态的制备及其操控，是超冷物理研究领域的前沿热点问题，对于精密测量物理、超冷量子化学以及量子信息处理等领域具有重要的科学意义与潜在的应用前景。结合Feshbach共振及光学泵浦等调控技术，超冷极性分子为实现新奇量子物态、强关联多体系统的可控量子模拟提供了全新的科学机遇。项目组在优化超冷钠铯极性分子超高真空实验系统的基础上，发展了多种高灵敏高分辨光谱技术与量子操控技术，增强了超冷分子光缔合光谱的探测灵敏度与信噪比，获得了超冷极性钠铯分子的光缔合光谱，并观测到了由于电子态微扰引起的极性分子的超精细结构，实现了外场对超冷极性分子量子态的高效操控。发展双光缔合光谱技术首次观测了极性分子超精细结构的光致频移。利用大功率远失谐激光构建了交叉的大体积光学偶极阱，实现了超冷钠-铯双组分原子的玻色量子气体，完成了温度为亚μK量级的超冷钠铯分子的高效装载。项目组利用Feshbach共振增强超冷原子的光缔合率，观测到非对称性的Fano线型，提出了超冷原子分子混合系统中耦合的Fano共振模型，通过构建原子-分子混合系统的跃迁通道获得了Fano量子态，实现了量子相干操控。项目执行期间共计发表标注项目资助的学术论文25篇（其中SCI收录24篇，包括Phys. Chem. Chem. Phys.、Phys. Rev. A、J. Chem. Phys.等SCI 高区论文12 篇；授权国家发明专利6项。项目研究成果荣获山西省科学技术奖一等奖1项。本项目为以超冷极性分子为介质的量子模拟、量子态操控等研究提供了科学与技术基础。