RESUMO
Based on the effective spin-ladder model, we study the properties of quantum dissonance (Q) between two edge spins in chiral graphene nanoribbons (CGNRs) thermalized with a reservoir at temperature T, and discuss the influences of relative location between two edge spins, ribbon width, temperature, and on-site Coulomb repulsion (U) on Q. The results show that Q is widely present in Wannier edge states. For intra-edge coupled spin pairs, quantum entanglement (E) is zero, but there still exists considerable value of Q. Interestingly, Q always keeps a constant for entangled edge spin pairs. Considering the thermal effect, it shows that Q always decays with the increasing temperature T, and the decay rate is very sensitive to the intensity of U. Compared Q with E and total quantum correlation (quantum discord, denoted by D), we conjecture that the quantum correlations for a bipartite Wannier edge state in CGNRs satisfy the relation Q ⩽ D-E.