Study On Coupling Of Mechanical Resonator And Solid Color Center

Effective control of quantum systems is an important basis for quantum information applications such as quantum computing,communication and sensing.In various quantum systems,solid-state color centers are very sensitive to many physical quantities in the environment,have a long coherence time at room temperature,and the initialization,reading and writing and manipulation of quantum states are very convenient,so they have attracted wide attention in recent years.However,because the color center is an atomic structure,this system has some limitations as well as the above advantages: for example,the in situ electrical control of the color center and the coupling of multiple color centers on the chip are still difficult to solve the bottleneck problems.In order to solve these problems,this thesis proposes an experimental idea of using mechanical resonator strain control to achieve in situ electrical regulation of solid color centers.Based on this,this thesis carries out two studies: one is to develop the reading and controlling system of solid color center based on NV color center;the other is to carry out the coupling study of mechanical resonator and solid color center based on twodimensional material color center.Two dimensional mechanical resonators are selected for their excellent electrical,optical and mechanical properties,simple preparation process,high adjustability,and easy integration with other optoelectronic platforms.Firstly,an experimental platform for the measurement of NV color centers was built,calibrated and optimized in this thesis to achieve the preparation of color centers and the characterization of spin characteristics.However,because diamond mechanical resonators are difficult to prepare and in situ control,this thesis proposes a scheme of in situ control of solid state color centers by coupling boron vacancy color center with mechanical resonator in two-dimensional material h BN.The NV color centers measurement and characterization technique in our early study is an important basis for our later study on in situ control of h BN color center.Based on the above scheme,this thesis designed and prepared the mechanical vibrator made of graphene and h BN heterostructure and the solid color center coupler.Dc and AC voltages were applied through the electrodes at the bottom of the vibrator.The DC voltage generated electric field force on the charged graphene to adjust the strain of the mechanical vibrator,and the AC voltage drove the heterogeneous vibrator to produce mechanical vibration.The objective is to realize the coupling of spin level and mechanical mode of color center in h BN and in situ control of color center by stress change.In practical experiments,we measured the change of color center luminescence spectra and optical probe magnetic resonance(ODMR)lines caused by stress changes.To understand the mechanism behind these phenomena,further theoretical and experimental studies by later researchers are still needed.There are two main innovations in this thesis: 1)The design of graphene and h BN heterojunction as a coupling system of mechanical vibrator and solid color center gives full play to the advantage of in situ electrical tunability of graphene mechanical resonator;2)It is found that the strain regulates the luminescence spectra and ODMR spectra.