Entanglement in helium

Przemysław Kościk, Jayanta K. Saha

Y.-C. Lin, Y. K. Ho

Y.-C. Lin, T. K. Fang, Y. K. Ho

Franck Laloë

J. S. Dehesa, Tsuyoshi Koga, Rafael J. Yáñez +2 more

We compute the entanglement of the ground state and several singlet and triplet excited states of the helium atom using high-quality, state-of-the-art wavefunctions. The behaviour of the entanglement of the helium eigenstates is similar to that observed in some exactly soluble two-electron systems. In particular, the amount of entanglement exhibited by the eigenstates tends to increase with energy.

Y.-C. Lin, Chih‐Yuan Lin, Y. K. Ho

Recently, there has been considerable interest in investigating 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 is investigated for the ground state and the singlet excited $1sn{s}^{1}S$ 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 is reported. Results are compared with the existing predictions.