Studies of Semiconductor Quantum Dots for Quantum Information Processing

In recent years, quantum information processing is of great theoretical and experimental interest. This new scientific field appears for people to devise and implement quantum-coherent strategies for computation and communication etc. A practical realization of a quantum computer would be quite significant, since there exist theoretical quantum algorithms which would make some classically hard computational problems tractable. Quantum communication is technologically very prospective because it offers the promise of private communication with unbreakable security assured by the laws of quantum mechanics. Quantum computation encompasses almost every possible quantum phenomenon in nature, so that it can be physically realized in many systems such as optical cavity, ion trap, superconductor, nuclear spin and electron spin [1]. However, serious conditions such as scalable quantum bit (qubit) system, initialization ability, long coherence time, universal gates and quantum measurement capability must be simultaneously satisfied for quantum computation [2]. Semiconductor quantum