论文标题
浮力涡流状态的光学电导率和轨道磁化
Optical conductivity and orbital magnetization of Floquet vortex states
论文作者
论文摘要
由于最近对Floquet拓扑绝缘子的实验演示的动机，有几个理论建议，用于使用空间或光谱的结构化光，以创建其他属性，例如平面带和涡流状态。特别是，已经提出了携带非零轨道角动量（OAM）的光照射的巨大的dirac fermion绝缘子中的涡流状态[Kim等。物理。 Rev. B 105，L081301（2022）]。在这里，我们将轨道磁化和光导率评估为这种系统的物理可观察力。我们表明，光的OAM诱导非零轨道磁化和电流密度。轨道磁化密度随着OAM度的函数而线性增加。在某些机制中，我们发现轨道磁化密度独立于系统的大小，宽度和光速频率。结果表明，由我们的浮雕理论引起的轨道磁化很大，可以通过磁力测量测量进行探测。此外，我们研究了系统中存在的各种状态（例如涡流，边缘和块状）之间各种类型的电子转变的光导率。根据电导频率峰，提出了检测涡旋状态的方案。
Motivated by recent experimental demonstrations of Floquet topological insulators, there have been several theoretical proposals for using structured light, either spatial or spectral, to create other properties such as flat band and vortex states. In particular, the generation of vortex states in a massive Dirac fermion insulator irradiated by light carrying nonzero orbital angular momentum (OAM) has been proposed [Kim et al. Phys. Rev. B 105, L081301(2022)]. Here, we evaluate the orbital magnetization and optical conductivity as physical observables for such a system. We show that the OAM of light induces nonzero orbital magnetization and current density. The orbital magnetization density increases linearly as a function of OAM degree. In certain regimes, we find that orbital magnetization density is independent of the system size, width, and Rabi frequency of light. It is shown that the orbital magnetization arising from our Floquet theory is large and can be probed by magnetometry measurements. Furthermore, we study the optical conductivity for various types of electron transitions between different states such as vortex, edge, and bulk that are present in the system. Based on conductance frequency peaks, a scheme for the detection of vortex states is proposed.
