Three kinds of ordering formulas for vacuum projection
operators and their applications
ZHANG Chun-zao1,REN Gang1,FAN Hong-yi2
1.School of Electronic Engineering,Huainan Normal University,Huainan,Anhui
232038,China;
2.Department of Material Science and Engineering,University of Science and
Technology of China,Hefei,Anhui 230026,China
ZHANG Chun-zao, REN Gang, FAN Hong-yi. Three kinds of ordering formulas for vacuum projection
operators and their applications[J].College Physics, 2019, 38(5): 5-.