Design And Study Of High Pressure Magnetic Resonance Apparatus Based On Diamond Nitrogen-Vacancy Center

Magnetic resonance has developed for eighty years,it can provide structural,dy-namic and kinetic information of materials to be detected fast and nondestructively.Magnetic resonance can be applied to investigate not only the crystal structure,elec-tronic structure and phases tracing of materials,but also chemistry reaction kinetics,biological macromolecules' structure and dynamics,etc.With the development of high pressure technology,high pressure apparatus mainly represented by diamond anvil cell(DAC)have achieved ultrahigh pressure above hun-dreds of giga pascal,and much attention has been paid to materials' properties under high pressure.High pressure will change the distances between the atoms or molec-ulars,increase the combination of electron orbit and change the energy structure that lead to structural phase transition and electronic phase transition.Magnetic resonance under high pressure can help to understand the essence of these phenomena,find new laws and materials so as to promote the development of high pressure physics.Traditional nuclear magnetic resonance(NMR)with induced-coils has to set the coils very close to sample to achieve high sensitivity which will face challenges under high pressure due to the tiny sample chamber volume of DAC.Coils placed inside the high pressure chamber will decrease the sample space leading to low signal-to-noise ratio of NMR experiment,while using larger diamond anvil which bring in larger sam?ple space will limit the DAC to achieve higher pressure.Optical detection magnetic resonance(ODMR)that is optically polarized and detected based on nitrogen-vacancy(NV)centers can perform magnetic resonance experiment under higher pressure with NV centers implanted in the shallow of diamond anvil.A high pressure magnetic resonance apparatus up to 30 GPa based on NV centers which is implanted in the shallow of diamond anvil of DAC is designed here.The design schemes of the high pressure apparatus is given.Parameters of the modules including the probe,exciting coils,detection optical system and magnets is determined in the arti-cle and simulation about the photon collection efficiency of NV fluorescence collection system is shown.Finally,we calculate the sensitivity of the designed apparatus with the parameters determined which is about 40.9 pT/(?)and verify that it can be used to perform high pressure magnetic resonance experiment.