Identification of the phosphorus-doping defect in MgS as a potential qubit

The P_(S) defect is obtained by replacing one S atom with one P atom in the wide-bandgap semiconductor Mg S.Based on first-principles calculations,the formation energy,defect levels,and electronic structure of the PSdefect in different charge states are evaluated.We predict that the neutral P^(0)_(S)and positively charged P^(+1)_(S)are the plausible qubit candidates for the construction of quantum systems,since they maintain the spin conservation during optical excited transition.The zero-phonon lines at the P^(0)_(S)and P^(+1)_(S)defects are 0.43 e V and 0.21 e V,respectively,which fall in the infrared band.In addition,the zero-field splitting parameter D of the P^(+1)_(S)with spin-triplet is 2920 MHz,which is in the range of microwave,showing that the P^(+1)_(S)defect can be manipulated by microwave.Finally,the principal values of the hyperfine tensor are examined,it is found that they decay exponentially with the distance from the defect site.