基于氮空位中心系综和声波谐振腔的纠缠相干态制备

Generation of Entangled Coherent States in Acoustic Wave Resonators Coupled to a Nitrogen-vacancy-center Ensemble

本文利用两个声波谐振腔与一个氮空位中心系综相耦合的系统设计了声波场纠缠相干态的制备方案。系统的两个声波谐振腔在一个平面内垂直交叉,氮空位中心位于交叉区域的中心位置。利用大失谐相互作用,我们可以实现声波场的最大纠缠相干态。系统间失谐的相互作用可以降低量子比特激发态衰减对于方案的不利影响,进而提高方案的实验可行性。此外,考虑声波场和固态比特耦合强度是非均匀的情况下,两个声波谐振腔系统末态的保真度仍然可以超过90%。

Recently,the study of the surface acoustic wave(SAW)in an acoustic wave resonator(AWR)and its interaction with microscopic particles have caused more and more attention.This paper proposes a scheme to prepare entangled coherent states on two AWRs coupled with a nitrogen vacancy(NV)center ensemble.The two AWRs cross each other vertically,and the NV ensemble is located at the center of the crossing.We first discuss the excited-state mediated spin-phonon coupling taking place in a-type three-level system for NV centers.Based on the large detuning interaction,we can achieve the maximally entangled coherent states of acoustic fields with a high probability of success and fidelity.The large detuning interaction can reduce the adverse impact from the decay process of the qubit excited state,thus improving the experimental feasibility of our scheme.The analysis results show that the fidelity of the final state can still be more than 90%under the condition of inhomogeneous qubit-resonator coupling strength.Moreover,under the existing experimental parameters,this scheme can be achieved within the coherence times of the NV centers and resonators.The NV centers in our scheme can be substituted by other emerging spin systems with spin defect centers such as quantum dots or superconducting systems,etc.Considering the macro-entangled coherent states have important applications in quantum information and quantum computing,the research results here have certain theoretical reference value for exploring the quantum acoustic properties and quantum information processing scheme with spin-phonon interaction system.