Basic Research Of Diamond Color Center Manufacturing Based On Ion Beam Bombardment

Single photon sources are the basis of many scalable quantum information technologies for quantum computers,quantum precision measurements,and quantum secure communication schemes.Diamond color center is a specific configuration combination of impurities and vacancies in diamond.It is a common point defect that can absorb visible light.Single diamond color center can output stable light without blinking or bleaching,which can be used as single photon source.At present,diamond color centers are mainly fabricated by electron beam irradiation,ion implantation,chemical vapor deposition,etc.Among them,ion implantation combined with annealing has become the most commonly used method with its high precision.However,ion implantation introduces dopant atoms and vacancies,as well as the damage of crystal lattice.Besides,the yield of color center formed by low-energy ion implantation is very low(<1%~10%),the manufacturing method and process need further exploration and research due to the randomness,controllability and reproducibility of the single silicon vacancy color center,related basic research work is imminent.In this paper,Molecular Dynamics(MD)and experimental methods are used to study the process of manufacturing diamond color center by ion implantation and annealing.Based on LAMMPS,the MD models of silicon ion bombardment into diamond and annealing are established,we simulate two key processes of ion implantation and annealing in silicon vacancy color center fabrication,and a variety of data analysis methods are used to analyze the damage,vacancy and other point defects,silicon atoms and SiV color center-related defects.The main research contents are as follows:(1)For the diamond annealing model after silicon ion implantation,based on the instability of the number of vacancies calculated by the Wigner-Seitz method,the LAMMPS NPT command parameters are optimized.It is found that the pdamp parameter has the greatest influence on the stable output of the number of vacancies in the annealing process.The parameter is optimized to achieve stable and reliable output of the characteristic defect value.(2)The effects of parameters such as implantation energy,angle and annealing temperature on damage and vacancies during bombardment and annealing process are analyzed.Based on the Identify Diamond Structure method,temperature and Radial Distribution Function,the phenomenon of self-annealing lattice repair during ion implantation and the dynamic repair process of damage and vacancies during annealing are revealed.(3)Based on the structural characteristics of silicon vacancy color centers,Python code is written to implement an algorithm for quickly and accurately identifying silicon vacancy color centers and their associated defects in a wide range of sample damage.The analysis strategy of silicon vacancy color center and related defects is proposed.Silicon atoms and defects such as double vacancy and(Si-V)before and after annealing are compared and analyzed.(4)Experimental study on the focused gallium ion beam implanting Ib diamond and annealing is studied.The fluorescence spectroscopy analysis proves that the nitrogen vacancy color center structure is successfully fabricated.At the same time,the method of using silicon ion implantation IIa diamond and annealing to manufacturing silicon vacancy color center is preliminarily studied.