Quantum entanglement in helium

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.Fil: Dehesa, J. S.. Universidad de Granada; EspañaFil: Koga, T.. Muroran Institute of Technology; JapónFil: Yanez, R.. Universidad de Granada; EspañaFil: Plastino, Ángel Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Granada; España. Universidad Nacional de La Plata. Centro Regional de Estudios Genómicos; ArgentinaFil: Esquivel, R. O.. Universidad de Granada; España. Universidad Autónoma Metropolitana; Méxic