论文标题
相互作用的两旋系统的拓扑电荷分布
Topological charge distributions of an interacting two-spin system
论文作者
论文摘要
量子系统通常用参数依赖性的哈密顿人描述。参数空间中两个级别退化的点可以带有拓扑电荷。在这里，我们从理论上研究了一个相互作用的两旋链系统，其中退化点在磁性参数空间中形成淋巴结环或淋巴结表面，与拓扑半学的频带结构中发现的这些结构类似。我们确定沿这些退化几何形状的拓扑电荷分布。我们表明，这些非点状的退化模式不仅可以通过微调来获得，而且可以通过空间对称性来稳定它们。由于此处研究的简单自旋系统在凝结物的设置中无处不在，因此我们希望我们的发现以及这些非平凡退化几何形状的物理后果在具有量子点，分子磁铁和金属表面上的Adatoms的实验中可以测试。
Quantum systems are often described by parameter-dependent Hamiltonians. Points in parameter space where two levels are degenerate can carry a topological charge. Here we theoretically study an interacting two-spin system where the degeneracy points form a nodal loop or a nodal surface in the magnetic parameter space, similarly to such structures discovered in the band structure of topological semimetals. We determine the topological charge distribution along these degeneracy geometries. We show that these non-point-like degeneracy patterns can be obtained not only by fine-tuning, but they can be stabilized by spatial symmetries. Since simple spin systems such as the one studied here are ubiquitous in condensed-matter setups, we expect that our findings, and the physical consequences of these nontrivial degeneracy geometries, are testable in experiments with quantum dots, molecular magnets, and adatoms on metallic surfaces.
