Quantum discord of electron spins of noninteracting electron gases

In this paper, we analyze the quantum discord of electron spins of noninteracting electron gases. Our results imply that the quantum discord depends on the relative distance between the two electrons and the temperature. By a comparison between the quantum discord and the entanglement of formation, we find that the quantum discord is more robust than the entanglement of formation in the sense that the quantum discord takes a zero value only at discrete points of the range of the relative distance whereas the entanglement of formation can disappear for a finite relative distance.