二维周期势阱中单原子物质波的操控与干涉

Investigation of the motional quantum behavior on single atom level is an important aspect in the research field of quantum physics. Manipulations of both the spin states and motional states of single atoms are basic techniques for the investigation of quantum behavior and quantum information based on single atoms. Once the single atoms are trapped in a micro-size potential the eigen-states of matter wave could appear and can be manipulated by lasers. In a periodic potential, the dynamic of single-atom matter wave shows unique quantum behavior and can be used to perform quantum simulation and quantum computation. Interaction between different atomic matter waves can also be used to produce entanglement between separate atoms. In this project, we are going to do research on manipulations and interference of single atom matter wave in a two dimensional periodic potential. The main work includes: 1. Manipulation of single atom matter wave in a micro-size optical trap; 2. Study of quantum behavior in the process of matter wave transportation and spread in periodic potential; 3. Study of interference between two or more single atom matter waves and the dependence of interaction on atomic spin sate; 4. Study of interference and interaction between atomic matter waves under decoherence and path noise. These investigations are significant to understand the dynamics and manipulation of single atom matter wave in periodic potentials.

单原子作为量子物理的基本系统，其自旋态和德布罗意波包振动态的完全操控是进行量子行为和量子信息研究的基础。在微尺度势阱中单原子具有明确的德布罗意波的振动态和振动能级，其振动态可以被精确操控。单原子波包在周期势阱中的动力学特性表现明显的量子特性，是量子模拟和量子信息研究的理想系统，同时多原子波包的相互作用也为量子纠缠的获得提供了新的途径。本项目拟开展二维周期势阱中单个中性原子波包的操控与干涉实验研究，主要包括：1.微尺度光阱中单个中性原子及其振动基态的制备和操控；2.振动基态的原子波包在周期势阱中的高效转移和扩散； 3.多个中性原子波包的干涉和相互作用研究以及原子自旋态对相互作用的影响；4退相干和路径噪声对原子波包干涉和相互作用的影响。该研究对认识单原子物质波在周期势阱中的动力学性质及操控具有重要意义。

单原子作为量子物理的基本系统，其自旋态和振动态的完全操控是利用其进行量子模拟和量子信息研究的基础，进而通过操控原子内态和光场相互作用可以实现新奇的量子器件。本项目研究取得的主要进展如下：1）实现了微尺度偶极阱中单原子内外态的操控，提出了一种全新的“三重魔术条件”光学囚禁原子方案，应用该方案可望将原子基态相干时间提高到一百秒量级，我们在实验上初步获得了6秒钟的红移阱中单原子相干时间。该方案对基于中性原子的量子模拟、量子信息处理及量子计算具有重要意义。2）实现了原子的空间长距离转移，利用光学腔的强耦合测量了原子的外态振动频率，同时实现了少光子光学非互易。该光学非互易传输机制利用了强烈的少原子量子非线性效应，为实现极弱光的无磁非线性光学非互易传输开辟了新的途径。3）作为基础研究带来的技术进步我们设计研制了一系列大数值孔径长工作距离显微镜头，不但能够满足单原子操控实验的需求，也能够用于其他需要大数值孔径和长工作距离显微镜头的工业、生物和材料监测的领域。