Study of Rydberg blockade in atomic vapor using 4-photon excitation

Abstract

In this thesis, 4-photon Rydberg excitation approach is used to study the Rydberg Blockade effect. In contrary to traditional approach, two-photon Rydberg excitation, we have shown that the Doppler effect can be neglected by reducing the wave vector mismatch. To study the blockade effect, the 5-level atomic system is first reduced to effective 2-level system via adiabatic elimination of intermediate state. Using two effective 2-level atom Rydberg blockade effect is studied by Monte-Carlo simulation. The effect of de-phasing in single Rydberg excited entangled state has also been observed by phenomenologically introducing a decay term in decay matrix. The second half of the thesis is mainly focused on the development of cold atom apparatus for Rb atom. The optical alignment and the current coils for magneto optical trap has been setup. The future direction of the cold atom experiment is to study the Anti-blockade effect in cold atom.