标题： 新兴的(2+1)维电动力学和伪厄米特双能级系统中的拓扑瞬子 显示英文标题

标题： Emerging (2+1)D electrodynamics and topological instanton in pseudo-Hermitian two-level systems

摘要： 我们揭示了一个隐藏的电磁动力学结构，该结构源自具有实谱的一般伪厄米系统$2\times2$。即使哈密顿量不显式依赖于时间，也可以将Berry曲率映射到一个来自人工时空瞬子的$2+1$维电磁场，这与厄米系统形成鲜明对比，在厄米系统中，Berry曲率等价于三维空间中磁单极子的静态磁场。 作为时空奇点出现的瞬子携带一个拓扑荷，该拓扑荷量化了Berry曲率在时间原点处的磁场跃迁。我们的发现在一个与反铁磁性磁振子相关的简单例子中得到了验证。 显示英文摘要

摘要： We reveal a hidden electrodynamical structure emerging from a general $2\times2$ pseudo-Hermitian system that exhibits real spectra. Even when the Hamiltonian does not explicitly depend on time, the Berry curvature can be mapped onto a $2+1$ dimensional electromagnetic field arising from an artificial spacetime instanton, in sharp contrast to the Hermitian systems where the Berry curvature is equivalent to the static magnetic field of a magnetic monopole in three spatial dimensions. The instanton appearing as a spacetime singularity carries a topological charge that quantizes the jump of magnetic flux of the Berry curvature at the time origin. Our findings are demonstrated in a simple example related to antiferromagnetic magnons.