高激发态原子多波混频实验进展研究

Research on Experimental Progress of Multiwave Mixing of High-excited Atoms

精确可控的量子信息比特载体是量子信息处理实用化进程中面临的一个重要核心问题。在物理学中,一些给定的物理体系可以作为信息载体,而信息处理及传输则是某些对应物理过程。就目前而言,在研究量子信息的实验中,相关的物理平台或者物理系统主要包括:超导体、线性光学、捕获离子以及半导体中的量子点等。高激发态原子的主量子数n通常非常大,它们有一些共性的特征:原子尺寸是基态原子的数千倍大,束缚能非常小,辐射寿命非常长,偶极矩非常大,偶极-偶极作用对电场非常敏感。这些特点使得中性高激发态原子成为实现量子逻辑运算最具潜力的信息载体。而作为一种重要的非线性光学过程,多波混频是指当N束任意频率的激光满足相位匹配条件作用于介质时,可以形成第N+1束频率为入射光频率各种和差组合的激光。可以用于频率转换,产生新的波长,在制备介关光子器件以及实现多光子纠缠源方面有着重要的意义和价值。

Accurate and controllable quantum information bit carrier is an important core problem in the process of quantum information processing.In physics,some given physical systems can be used as information carriers,while information processing and transmission are some corresponding physical processes.At present,in the research of quantum information experiments,the related physical platforms or systems mainly include superconductors,linear optics,trapped ions and quantum dots in semiconductors.The main quantum number n of highly excited atoms is usually very large,and they have some common characteristics:the atomic size is thousands of times larger than that of the ground state atoms,the binding energy is very small,the radiation lifetime is very long,the dipole moment is very large,and the dipole dipole interaction is very sensitive to the electric field.These characteristics make the neutral highly excited atoms become the most potential information carrier for quantum logic operations.As an important nonlinear optical process,multi wave mixing means that when N laser beams of any frequency meet the phase matching condition,the N+1 laser beams with different sum and difference combinations can be formed.It can be used for frequency conversion and generation of new wavelengths.It has great significance and value in the preparation of dielectric photonic devices and the realization of multiphoton entanglement source.