Studies On Solid-state Electron Spin Polarization And Vector Magnetic Field Measurement Mechanism

In recent years,the nitrogen vacancy(NV)center,as an excellent solid state electron spin quantum system,has a long coherent time at room temperature and is easily read out by laser radiation,which has made a breakthrough in the field of quantum control and quantum sensing.Meanwhile,using microwave and radio frequency technology to control the spin state of NV color center can realize the quantum precise magnetic detection.Combining with its structure symmetry,the use of multi-frequency microwave pulse synchronization to control the different crystal axes of NV color center can also improve its vector magnetic measurement sensitivity.Therefore,it has become our research goal to realize high-sensitivity magnetic detection on precise manipulation of solid-state electron spin.The main research contents are as follows:Firstly,we give a brief introduction to the current research level and research methods of solid-state electron spin polarization and vector magnetic field measurement.The basic properties of NV color center are essentially introduced in essence: including physical,electronic,energy level structure and spin polarization mechanism.At the same time,the processing technology and spectral characteristics of NV color center are introduced.Several spin control methods and principles based on optical detection magnetic resonance technology are analyzed.The principle of vector magnetic measurement and the measurement method of sensitivity are summarized.Secondly,in order to realize the solid-state electron spin polarization,we take the generation of high-precision synchronous timing pulses as the research objective,and design the pulse sequence generating module and data acquisition,storage and operation module based on Labview and spincore,to realize the synchronous operation between differentinstruments.Simultaneously,the pulse sequence was designed to realize the spin manipulation experiment.Combined with the the self-built software and hardware system,the Rabi oscillation period of the ensemble NV color centers was measured as 300 ns.The spin echo and decoherence time of the NV color centers were also measured by experiments,and the experimental control parameters were optimized.Finally,the spatial mathematical modeling of the vector magnetic field measurement was carried out according to the structural symmetry of the NV color center.The relationship between the magnitude and direction of the magnetic field and the NV axis was theoretically derived and verified by experiments.The relationship between vector magnetic field and key parameters such as rabi oscillation was also studied.The experiment realizes the measurement of solid-state electron spin polarization and vector magnetic field by using microwave and laser technology,which provides a good experimental platform for prolonging the decoherence time and improving the sensitivity of magnetic detection.