We give a brief overview of some basic concepts in quantum information processing, and discuss various systems considered to implement these ideas. We focus our attention on one particular system, ultracold Rydberg atoms, and show how the strong interaction between such atoms can be used to implement an universal quantum logic gate, namely a phase gate. We also describe how quantum information can be stored and manipulated in mesoscopic ensembles of such atoms. We present some experimental results on the effects of strong interactions between Rydberg atoms.
"Quantum computing with Rydberg atoms", Proc. SPIE 6014, Active and Passive Optical Components for WDM Communications V, 601415 (24 October 2005); doi: 10.1117/12.631327; https://doi.org/10.1117/12.631327