Magnetism of competing high-spin/low-spin states in Ba2NiO2(AgSe)2 and related two-orbital two-electron systems
Magnetism of competing high-spin/low-spin states in Ba2NiO2(AgSe)2 and related two-orbital two-electron systems
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DOI：
10.1103/physrevb.105.064406
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发表时间：
2021-08
影响因子：
3.7
通讯作者：
Rajiv R. P. Singh
中科院分区：
文献类型：
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作者：
Rajiv R. P. Singh
我们讨论了一个正方晶格上的竞争高自旋/低自旋双轨道双电子模型的热力学和磁学性质，该模型可能与镍酸盐Ba_2NiO_2（AgSe）_2（BNOAS）有关。我们专注于高自旋（S = 1）和低自旋（S = 0）状态的参数制度，在能量上彼此接近，并讨论在这样的系统中的各种交换过程。我们研究的模型是一个变种，但不同的近藤项链模型提出的系统由Jin等人[1]。虽然这两个模型在基态相位和对称性方面有相似之处，但不同相位和相变的详细性质是完全不同的，从实验的角度来看应该很容易区分。
We discuss the thermodynamic and magnetic properties of a competing high-spin/low-spin two-orbital two-electron model on a square-lattice possibly relevant to the nickelates such as Ba2NiO2(AgSe)2 (BNOAS). We focus on parameter regimes where a high-spin (S = 1) and a low-spin (S = 0) state are energetically close to each other and discuss various exchange processes in such a system. The model we study is a variant of, but different from the Kondo-necklace model proposed for the system by Jin et al [1]. Although there are similarities between the two models in terms of the ground-state phases and their symmetries, the detailed properties of the different phases and the phase transitions are entirely different and should be easy to distinguish from an experimental point of view.