Quantum coherence and its distribution in a two-dimensional Heisenberg XY model

Abstract

We investigate quantum phase transitions in the two-dimensional Heisenberg XY system. A basis-independent measure that is square root of quantum Jensen–Shannon divergence is used to identify quantum phase transitions. This method is suitable for discussing the multipartite coherence in the quantum spin system. By analyzing the local coherence and collective coherence in the model, we find that both quantities can effectively detect the critical point and they will exhibit a trade-off relation. When close to the quantum critical point, the scaling behavior are obtained for both measures. We also studied the distribution of quantum coherence and it was found that the reduced tripartite system is polygamous and the five-site block state does not obey additivity relation.