基于微米气室里德堡原子实现单光子的存储和纯化

Many architectures rely on efficient interfaces between single photon and single material quantum systems which serve as flying qubits and storage qubits respectively. Efficient matter-field coupling on the single–photon level is a key ingredient for quantum technologies. In order to realize such devices, basic generation, storage, state control and production protocols at single-particle or single-photon level have to be developed. In order to control the interaction, atom coupling with selected electromagnetic field modes has to be enhanced. Engineering quantum many-body systems with a high degree of control and tunable interactions is an active field of research as it is a prerequisite for quantum information processing and quantum simulation. Motived by the demand for quantum communication and quantum information processing, goals of this experiment,.(1) We perform the deterministic single atom loading in micrometer size optical dipole trap with the help of optical feedback control. We demonstrate the generation of a triggered single-photon source based on single cesium atom..(2) We investigate the excitation of Rydberg atoms by combination of single-photons，multi-photons and microwave fields, study the properties of spectroscopic of high Rydberg levels. We study the states interaction properties of Rydberg atom, including collective interaction and nonlinear;.(3) We design and assemble the micrometer glass cell, where one dimension size is smaller than the radius of Rydberg blockade and the other two dimensions size is limited by the size of focused laser beam; We study the single atom excitation by the Rydberg spin wave in room temperature atomic cell, which can be used for performing single photon storage in atomic ensemble..(4) We use the uniform-spin wave to storage the optical pulse single in single photon level, achieve well defined single photon spatial mode from collective spin wave of different atoms. This allow filtering of stored excitation pulses and realization of dissipative sing-photon transistors. Achieve the controlled Rydberg-dressed interaction allow to study the strong interactions between qubits lead to spatial correlations in these many-body systems.

量子比特是量子通讯和量子信息处理的基本单元。基于单光子作为飞行比特，基于原子作为存储比特，可用于构建量子中继器，实现量子网络的链接。量子中继过程依赖光子-原子的信息交换，其核心是单光子的可控存储和读取。通过局域空间里德堡原子的集体效应可以调控光子-原子的耦合，实现单光子的量子寄存器，为量子中继提供解决方案。拟在本项目的支持下，利用系综里德堡原子与光子的强耦合实现单光子的存储。研究内容包括：（1）利用大失谐动态注入锁定方案产生可调谐脉冲光源，基于单原子的脉冲激发实现单光子源；（2）研究微米气室里德堡原子的集体效应和非线性效应，实现可控的系综原子长程相互作用；（3）研究里德堡原子与单光子的耦合特性，实验实现单光子在室温原子中的存储和读取；研究系综原子的激发阻塞效应，实现光子滤波和纯化；（4）探索利用运动不敏感的集体相互作用调控单光子辐射的时间模式和空间模式。

本项目按照研究计划执行，基于激光冷却技术构建单原子平台，利用单原子脉冲激发实现触发式单光子源，实现单光子偏振的模式调控；基于微尺度系综里德堡态原子制备具有长程相互作用的非线性介质，构建电磁场敏感的双稳态，并用于新型量子光源产生和量子精密测量。利用大失谐动态注入锁定方案产生可调谐纳秒脉冲光源，基于单原子的脉冲激发实现单光子源；完成用于里德堡原子激发的大功率纳秒脉冲光源与连续光源；基于室温里德堡原子实现双稳态，利用双稳态实现单光子水平的量子随机数；实验证实了微气室中系综原子的集体效应导致的光谱压窄，实现单光子水平弱光的时间模式、频率模式调控；单光子辐射空间模式调控还需要后续理论与实验研究进一步完善。