Quantum coherence rather than quantum correlations reflect the effects   of reservoir on the system's work capability
  We consider a model of an optical cavity with a nonequilibrium reservoir consisting of a beam of identical two-level atom pairs (TLAPs) in the general X-state. We find that coherence of multiparticle nonequilibrium reservoir plays a central role on the potential work capability of cavity. We show that no matter whether there are quantum correlations in each TLAP (including quantum entanglement and quantum discord) or not the coherence of the TLAPs has an effect on the work capability of the cavity. Additionally, constructive and destructive interferences could be induced to influence the work capability of cavity only by adjusting the relative phase with which quantum correlations have nothing to do. In this paper, the coherence of reservoir rather than the quantum correlations effectively reflecting the effects of reservoir on the system's work capability is demonstrated clearly. 
Hai Li, Jian Zou, Wen-Li Yu, Bao-Ming Xu, Jun-Gang Li, and Bin Shao
quant-ph