Single Photon and Single Atom Sources for Quantum Information Processing

EIA-0218341威斯康星大学麦迪逊分校Mark Saffman用于量子信息处理的单光子和单原子源这项研究项目正在展示在量子信息科学的一系列应用中设计单光子和单原子源的新方法。实验方法从数千个Rb原子开始，这些原子被囚禁在远距离共振光束中的超高密度下。然后利用Lukin等人最近提出的在密集原子蒸气中原子-原子相互作用产生的偶极阻塞机制来创建多原子纠缠态。(2001)。被捕获的纠缠原子系综被光学操纵，以在单原子和单光子水平上创建新的源。使用附加的近共振激光光束，根据原子的内部状态，原子被选择性地从陷阱中弹射出来。这使得能够将单个原子确定性地加载到光学陷阱中，以及具有光学可控轨迹的“单原子”或“按需多原子”源。通过使用基态和激发内态原子之间的纠缠，可以创建具有衍射限制的、可控制的发射图案的单光子源。这种方法使许多新的解决方案能够在单个量子对象的水平上操纵物质和场，并将其应用于量子通信、密码学和计算。这项工作的一个重要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面向普通公众的量子信息和计算讲座使威斯康星大学能够与当地社区，包括麦迪逊地区蓬勃发展的光电子业，交流这一研究项目的重要性和智力上的兴奋。

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.