论文标题
分析三级Lipkin模型基底状态内的量子相关性
Analysis of quantum correlations within the ground state of a three level Lipkin model
论文作者
论文摘要
超出平均场方法在解决量子的量子中，许多人体问题的性能通常以相对于基础平均场值测量的相关能量。在本文中，我们解决了从量子信息的角度来表征与不同近似相关的相关量的问题。考虑到这一目标，我们以自发对称性破坏的传统Hartree-fock（HF）方法分析了具有对称性恢复的HF和以三级Lipkin模型的精确溶解费用模型中的对称性恢复和生成器坐标方法（GCM）。为了表征包括纠缠和超越的相关性，我们使用不同分区轨道之间的量子不一致。我们发现，对于出于物理的动机分区，确切的基态的量子不和谐通过不同的近似值很好地重现。但是，其他分区创建“假量子相关”，以捕获与Hartree-Fock解决方案失败的分区相对应的量子相关。这些被删除并通过对称恢复过程重新分布。
The performance of beyond mean field methods in solving the quantum many body problem for fermions is usually characterized by the correlation energy measured with respect to the underlying mean field value. In this paper we address the issue of characterizing the amount of correlations associated to different approximations from a quantum information perspective. With this goal in mind, we analyze the traditional Hartree-Fock (HF) method with spontaneous symmetry breaking, the HF with symmetry restoration and the generator coordinate method (GCM) in a exactly solvable fermion model known as the three-level Lipkin model. To characterize correlations including entanglement and beyond we use the quantum discord between different partition orbitals. We find that for physically motivated partitions, the quantum discord of the exact ground state is reasonably well reproduced by the different approximations. However, other partitions create "fake quantum correlations" in order to capture quantum correlations corresponding to partitions for which the Hartree-Fock solution fails. Those are removed and redistributed through a symmetry restoration process.
