By studying the two operators used in quantum searching, we find the similarity between the quantum searching and the course of two body elastic collision. This similarity can help one to understand quantum coherence.
Quantum decoherence behavior is observed and studied on a 2 qubit NMR quantum computer. Experimental results show a good agreement between theory and experiment. The scheme can be generalized to the case that the environment is composed of N independent qubits.
The improved quantum scheduling algorithm proposed by Grover i s generalized and realized on a nuclear magnetic resonance (NMR) quantum c omputer. Experimental results show a good agreement between theory and experimen t.
An entangled state is prepared using nuclear magnetic resonance (NMR). And its attribute is shown in NMR spectra. The relation between quantum entanglement and coherence is discussed by studying the evolution of entangled state under decoherence.