Single Photon and Single Atom Sources for Quantum Information Processing

EIA-0218341 Mark Saffman威斯康星大学麦迪逊分校用于量子信息处理的单光子和单原子源该研究项目展示了工程单光子和单原子源在量子信息科学中的一系列应用的新方法。实验方法从几千个Rb原子开始，这些原子被困在一个远离共振的光束中，密度为1000。然后利用Lukin等人（2001）提出的偶极阻塞机制，在稠密原子蒸气中产生多原子纠缠态，并对纠缠原子系综进行光学操纵，在单原子和单光子水平上产生新的光源.使用额外的近共振激光束，原子根据其内部状态选择性地从陷阱中射出。这使得能够确定性地在光阱中加载单个原子，以及具有光学可控轨迹的“单原子”或“多原子按需”源。 通过利用基态和激发态原子之间的纠缠，正在创建一个具有衍射限制的可操纵发射模式的单光子源。这种方法使许多新的解决方案能够在单量子物体的水平上操纵物质和场，并应用于量子通信，密码学和计算。这项工作的一个关键组成部分是通过外联和教育活动加强其影响。在当地学校的演讲和讲座，为公众提供量子信息和计算，使威斯康星州的大学沟通到当地社区，包括在麦迪逊地区，这个研究计划的重要性和智力兴奋新兴的光子产业。

EIA-0218341Mark Saffman University of Wisconsin-MadisonSingle-Photon and single atom sources for quantum informaiton processingThis research project is demonstrating new ways of engineering single photon and single atom sources for a range of applications in quantum information science. The experimental approach starts with several thousand Rb atoms that are trapped at ultrahigh densities in a far-off-resonance optical beam. A many atom entangled state is then created using the dipole blockade mechanism that arises from atom-atom interactions in a dense atomic vapor as proposed recently by Lukin, et al. (2001).The trapped ensemble of entangled atoms is manipulated optically to create novel sources at the level of single atoms and single photons. Using additional near-resonant laser beams atoms are selectively ejected from the trap depending on their internal state. This enables deterministic loading of a single atom in an optical trap, as well as "single-" or "multiple-atom-on-demand" sources with optically controllable trajectories. By using entanglement between atoms in ground and excited internal states a single-photon source is being created that has a diffraction limited, steerable emission pattern. This approach is enabling a number of novel solutions to manipulation of matter and fields at the level of single quantum objects with applications to quantum communication, cryptography, and computing. A key component of this work is the enhancement of its impact through outreach and educational activities. Presentations at local schools and lectures for the general public on quantum information and computation are allowing the University of Wisconsin to communicate to the local community, including the burgeoning photonics industry in the Madison area, the importance and intellectual excitement of this research program.