Imaging Spatial Correlations of Rydberg Excitations in Cold Atom Clouds.

Abstract

When cold atoms are laser-excited to Rydberg states, the strong interactions between Rydberg excitations can lead to complex many-body entanglement in the system. The excitation process results in spatial correlations between excitations in the system. In most cases, Rydberg excitation positions are anticorrelated such that no two excitations are within a "blockade radius" of each other. Such systems are well-suited for studying basic many-body physics, as well as for future technological applications such as quantum computation.

This thesis describes an experimental apparatus we constructed to perform spatially-sensitive detection of Rydberg atoms. We use the apparatus to perform measurements of the Rydberg-Rydberg pair-correlation function. This results in the first direct spatial images of the Rydberg blockade effect. We measure the blockade radius for a variety of S and D Rydberg states in rubidium. We investigate the dependence of the blockade radius on laser detunings and energy level shifts induced by optical potentials due to trapping lasers. Our results have some implications for atom traps used for neutral atom quantum computation. We also present simulations results used to characterize the performance of the imaging system.