Quantum Information Processing Based On Hybrid Quantum System

Quantum information is information that is stored and processed in quantum systems.As compared with classical information,quantum information has unique advantages such as low resource overhead,large storage capacity,fast processing speed and high security of transmission.In the last decade,the development of quantum information has extended from theory to experiment and towards practical applications.In the field of quantum information,finding stable physical systems and realizing effective coupling between different physical systems represent important research directions.In this thesis,we systematically investigate hybrid solid-state quantum systems which consist of solid-state spin and mechanical oscillator.We present analytical treatment of such solid-state hybrid quantum systems.Based on the model,we propose two schemes for the implementation of entangling gate and entanglement generation between distant solid-state electron spins and nuclear spins.The main contributions and novelty of the thesis include:(1)The hybrid system of mechanical oscillator and solid-state spins is scalable.By using selective microwave driving,our scheme is able to realize an effective coupling between two specific solid-state spins,while the other undriven spins remain decoupled.The scheme takes advantage of decoherence free subspace,reduces the thermal effect of mechanical oscillator to the fourth order,and thereby relaxes the requirement for cooling of mechanical oscillator in experiment.Furthermore,we propose to realize entangling quantum gate between distant solid-state spins and analyse the effect of decoherence in detail.(2)We present a new hybrid system that consists of mechanical oscillator,electron spins and nuclear spins in nitrogen-vacancy center of diamond.Based on the induced interaction between nuclear spins via mechanical oscillator and electron spins,we propose a scheme to realize entangling quantum gate between distant nuclear spins,which represents a scalable architecture for nuclear spin based quantum information processing.Furthermore,we discuss how to generate multi nuclear spin graph state and analyse the effect of decoherence in detail.