Quantum discord of SU(2) invariant states

Abstract

We have analytically calculated the quantum discord for a system composed of spin-$j$ and spin-1/2 subsystems possessing SU(2) symmetry. We have compared our results with the quantum discord of states having similar symmetries and seen that in our case amount of quantum discord is much higher. Moreover, using the well known entanglement properties of these states, we have also compared their quantum discord with entanglement. Although the system under consideration is separable nearly all throughout of its parameter space as $j$ increases, we have seen that discord content remains significantly large. Investigation of quantum discord in SU(2) invariant states may find application in quantum computation protocols that utilize quantum discord as a resource since they arise in many real physical systems.