Quantum information science makes the promise for superfast computation, simulation, and secure communication based on fundamental principles of quantum mechanics. A critical problem in this field is how to implement these novel computation and communication models with real physical systems. The challenge for implementation of quantum computation and communication is due to the inevitable decoherence (noise) effect inherent in any real physical systems. In this project, we will develop a multi-facet theoretical program to attack this main challenge. We will investigate a variety of physical systems, ranging from nano-scale quantum dots, to micrometer-scale cavity QED and trapped ion systems, and to macroscopic atomic ensembles. We look for realistic quantum computation and communication schemes which show inherent robustness to practical noise in the corresponding systems. We will develop methods to significantly advance coherent control techniques and implementation of quantum information in the above physical systems.
