Spatial entanglement in two-electron atomic systems
Yen-Chang Lin, Chih-Yuan Lin, and Yew Kam Ho
Accepted
Recently, there have been considerable interests to investigate quantum entanglement in two-electron systems, such as two-electron model atoms and quantum dots. In this work, the quantum entanglement of the helium atom and helium-like ions are explored using the two-electron wave functions constructed by the B-spline basis. As a measure of the spatial entanglement, the linear entropy of the reduced density matrix are investigated for the ground state and the singlet excited 1sns 1S states, with n=2-10, of the helium atom. The variation of the spatial entanglement with the nuclear charges Z=2-15 for the helium-like ions are reported. Results are compared with the existing predictions.