Sudden Transition in Quantum Discord Dynamics: Role of Three-Site Interaction

We investigate the dynamics of quantum discord for a two-qubit system coupled to a spin chain with three-site interaction in the weak-coupling region. For the case of the initial two-qubit pure state, the decay of quantum discord can be delayed in a special interval of the three-site coupling strength. In the absence of the transverse field, with the increase of three-site interaction, quantum discord tends to be stabler. For the case of the initial mixed state, the increase of quantum discord is delayed in the special interval of three-site interaction. In addition, a sudden transition between classical and quantum decoherence is also observed, with the transition time determined by the three-site interaction and degree of anisotropy.