PhD Proposal: Garrett Hickman
Thursday, May 1, 2014 · 1 - 3 PM
TITLE: Single Photon Cross Phase Shifts using Metastable Xenon in a High Finesse Optical Cavity
ABSTRACT: Advances in the theory of quantum computing, such as Shor's algorithm for factoring large numbers, raise doubts about whether conventional encryption will be able to provide confidential long-distance communications in the near future. The achievability of confidential communications may depend on schemes that can guarantee security based solely on the laws of quantum mechanics. Many such schemes exist, but they are limited to relatively short communication distances. A new scheme has recently been proposed to overcome this shortfall by using phase entangled macroscopic coherent states of light as carriers of information. The most important component in an experimental realization of this scheme, and the most difficult to build, is a device for producing significant cross phase shifts on a coherent state light beam, depending solely on the presence or absence of a single photon. Here I propose to experimentally demonstrate single-photon cross phase shifts using metastable xenon vapor in a high finesse optical cavity, and to measure them with high signal-to-noise ratio (SNR) >~1 in a single-shot pulse-based setup. Time permitting, a full-scale experimental system will also be built to test the performance of the new scheme.
ABSTRACT: Advances in the theory of quantum computing, such as Shor's algorithm for factoring large numbers, raise doubts about whether conventional encryption will be able to provide confidential long-distance communications in the near future. The achievability of confidential communications may depend on schemes that can guarantee security based solely on the laws of quantum mechanics. Many such schemes exist, but they are limited to relatively short communication distances. A new scheme has recently been proposed to overcome this shortfall by using phase entangled macroscopic coherent states of light as carriers of information. The most important component in an experimental realization of this scheme, and the most difficult to build, is a device for producing significant cross phase shifts on a coherent state light beam, depending solely on the presence or absence of a single photon. Here I propose to experimentally demonstrate single-photon cross phase shifts using metastable xenon vapor in a high finesse optical cavity, and to measure them with high signal-to-noise ratio (SNR) >~1 in a single-shot pulse-based setup. Time permitting, a full-scale experimental system will also be built to test the performance of the new scheme.
