Quantum Decoherence Of Charge Qubit Coupled To Nonlinear Nanomechanical Resonator

This article analyzes the background of quantum information, it explores theresearch history and present situation of quantum computer, the basis of quantumcomputer research is quantum computation, quantum device and quantum informationstorage, etc., and the fundamental requirement of quantum information is quantumcoherence. Quantum coherence will reduce the computational power. At present thebiggest obstacle of quantum computation is quantum decoherence. Experimental andtheoretical studies have studied the effect of quantum decoherence in order toovercome the bad effect, Recently in solid state based quantum computation,Josephson Junction qubits demonstrate their large potential as a candidate of a scalablequantum computation. The nanomechanical resonant, atom field interaction model,and JC model are analyzed. It is well known that any real system will be interactionwith the background, the nonlinearity of nanomechanical resonator is considered in thepaper when we research coupled system.When the nonlinearity of nanomechanical resonator is not negligible, the quantumdecoherence of charge qubit is studied analytically. Using nonlinear Jaynes-Cummingsmodel, one explores the possibility of being quantum data bus for nonlinearnanomechanical resonator, the nonlinearity destroys the dynamical quantuminformation-storage and maintains the revival of quantum coherence of charge qubit.With the calculation of decoherence factor, we demonstrate the influence of thenonlinearity of a nanomechanical resonator on the engineered decoherence of chargequbit.