Thermal state quantum correlation in lithium atom

In this paper we perform a comparative investigation on the quantum correlation and quantum entanglement between the electron and the nucleus in the lithium atom in the presence of magnetic field both for zero temperature case and finite temperature case. The quantum correlation and quantum entanglement are quantified by quantum discord and negativity respectively. It is found that compared with negativity, the quantum discord shows quite different behaviors at the same temperatures and magnetic fields. The quantum discord is more robust than quantum entanglement, so it is expected to be more useful in the processing of quantum information and quantum computation.