Quantum State Manipulation Based On Nitrogen-vacancy Centers In Diamond

With the continuous development of society and technology,people have higher requirements for information security and information processing speed in the face of huge amounts of information.As a new subject,quantum information not only covers the classical information and the theoretical knowledge of classical subjects,but also absorbs the part of quantum mechanics that is superior to the classical information.Therefore,quantum information has shown its unique potential in information processing and computing.Quantum information science,with the help of the No-Cloning Theorem and parallel operation of quantum mechanics,is incomparable to the classical information in terms of information security and computing speed.Quantum information and quantum computing are becoming a popular research area in information computing.In quantum information,choosing a suitable carrier of quantum information with superior performance is a crucial step in the computation and processing of quantum information.At present,the experimental research on quantum information carrier has also made great progress,and the purpose of carrying quantum information has been achieved in ion hydrazine,nuclear magnetic resonance,quantum dots,diamond nitrogen vacancy center and other systems.Among them,NV centers have the advantages of easy manipulation of electron spins and long coherence time of nuclear spins,which have great potential in quantum information and quantum computing,and thus have been widely used.This article mainly involves the following aspects:First we propose a scheme for deterministic measurements of two-photon Bell states using parity gates in combination with quantum logic gates.In the scheme,quantum logic gates such as C-NOT gates are implemented by using the property that parity gates do not change the photon state during the measurement.Quantum logic gates are used to perform state measurements of the two-photon Bell state by taking two readings of the auxiliary qubits.In the paper we extend the scheme to three-photon GHZ states for probabilistic nondestructive measurements.Secondly,we propose a scheme to generate Bell states using nuclear and electronic spins in nitrogen vacancy centers for quantum state manipulation through a series of quantum gates.In the process of quantum state manipulation,it is necessary to measure the Bell state.In order to avoid the state collapse due to the measurement,the entangled state composed of electron and nuclear spin is converted into a two-photon entangled state.Then use the scheme of deterministic measurement and discrimination of the two-photon Bell state mentioned in the article for identification.Finally,quantum logic gates such as C-NOT gates are used to realize the manipulation of quantum states.This scheme may provide new ideas for quantum state transfer and quantum information processing based on diamond nitrogen vacancy centers.