Quantum Optics in RB-Filled Photonic Crystal Fibers

这个项目将研究光与物质的相互作用，这些物质被如此强烈地增强，以至于单个光子可以改变其他光子的传播。这种强烈的增强将通过向被称为光子晶体光纤的特殊中空纤维的核心中注入Rb原子来实现，这种纤维可以在比在自由空间实现的更长的距离内对光进行严格限制。将研究各种相互作用，这些相互作用可能对量子信息科学具有重要应用，并可能用于高度安全的通信和量子计算。特别是，这三个项目的成功实现可能会带来一系列重要的量子器件，包括可扩展的单光子源、确定性量子逻辑门和量子中继器。光子带隙光纤(PBGF)通过衍射而不是全内反射来引导光，并允许光和气体在空心区同时进行高限制。因此，由于其无与伦比的路径长度与核心横截面面积的比率，光子晶体光纤为原子-光相互作用提供了相对于自由空间、聚焦几何结构的独特优势。拟议的工作将由三个项目组成，这些项目建立在首席调查员最近成果的基础上。第一个项目将探索单光子诱导的非线性相移及其在量子非破坏测量中的应用。第二个项目需要通过布拉格散射四波混频的非线性过程，利用频率转换过程，在亚毫瓦功率下演示光场的频率转换及其量子性质。第三个项目将研究相干光子转换过程，在这个过程中，三个量子场经历了由强泵浦光场介导的强非线性相互作用。这些项目不仅将解决基本问题，如每个光子是否可能出现大的非线性相移，还将探索基于Rb的PBGF系统是否能够实现其作为量子信息应用平台的承诺。

This project will study interactions of light with matter that are so strongly enhanced that single photons can alter the propagation of other photons. This strong enhancement will be achieved by injecting Rubidium atoms into the core of special hollow fibers, known as photonic crystal fibers, which can tightly confine the light over distances much longer than could be achieved in free space. Various interactions will be studied which could have important applications to quantum information science and could be used for highly secure communications and for quantum computing. In particular, successful realization of the three projects making up the effort could lead to a number of important quantum devices including scalable single-photon sources, deterministic quantum logic gates, and quantum repeaters.Photonic band-gap fibers (PBGF) guide light via diffraction rather than by total internal reflection and allow for simultaneous high confinement of light and gases in a hollow-core region. As a result, PBGF's offer a unique advantage over free-space, focused geometries for atom-light interactions due to their unmatched ratio of path length to cross-sectional core area. The proposed effort will consist of three projects that build on the principal investigator's recent results. The first project will explore nonlinear phase shifts induced by single photons and its use for quantum non-demolition measurements. The second project entails demonstration at sub-milliwatt powers of frequency translation of a light field and its quantum properties using the process of frequency translation via the nonlinear process of Bragg scattering four-wave mixing. The third project will investigate the process of coherent photon conversion in which three quantum fields undergo a strong nonlinear interaction that is mediated by a strong pump field. These projects will address not only fundamental issues, such as whether large nonlinear phase shifts per photon are possible, but also will explore whether the Rubidium-based PBGF system can fulfill its promise as a platform for quantum information applications.