论文标题
由于Rashba自旋 - 轨道相互作用而引起的反向法拉第效应的理论：带分散和费米表面的作用
Theory of the Inverse Faraday Effect due to the Rashba Spin-Oribt Interactions: Roles of Band Dispersions and Fermi Surfaces
论文作者
论文摘要
从理论上讲，我们通过特别关注具有自旋轨道相互作用（SOI）的晶体系统中带分散体和费米表面的效应，从理论上研究了逆法拉迪效应，即用圆极化光的自旋极化的光学诱导。通过用Rashba型SOI的数值求解与时间相关的时间相关模型的时间相关模型，我们分别复制了光诱导的自旋偏振，与$ e_0^2/ω^3 $成正比，其中$ e_0 $和$ e_0 $和$ω$分别是电场振幅和光的光频率。这种光自旋诱导归因于光电场和由SOI介导的电子旋转之间的动态磁电耦合。我们阐明诱导自旋极化的大小和符号敏感地取决于电子填充。为了理解这些结果，我们构建了基于浮点定理的分析理论。该理论成功地解释了$ e_0 $和$ω$的依赖性，并将电子填充依赖性归因于受费米 - 表面几何形状控制的动量依赖的有效磁场。还讨论了与我们的理论和模型参数相关的几种候选材料和实验条件。我们的发现将使我们能够通过调整材料参数来设计物质的磁光响应。
We theoretically study the inverse Faraday effect, i.e., the optical induction of spin polarization with circularly polarized light, by particularly focusing on effects of band dispersions and Fermi surfaces in crystal systems with the spin-orbit interaction (SOI). By numerically solving the time-dependent Schrödinger equation of a tight-binding model with the Rashba-type SOI, we reproduce the light-induced spin polarization proportional to $E_0^2/ω^3$ where $E_0$ and $ω$ are the electric-field amplitude and the angular frequency of light, respectively. This optical spin induction is attributed to dynamical magnetoelectric coupling between the light electric field and the electron spins mediated by the SOI. We elucidate that the magnitude and sign of the induced spin polarization sensitively depend on the electron filling. To understand these results, we construct an analytical theory based on the Floquet theorem. The theory successfully explains the dependencies on $E_0$ and $ω$ and ascribes the electron-filling dependence to a momentum-dependent effective magnetic field governed by the Fermi-surface geometry. Several candidate materials and experimental conditions relevant to our theory and model parameters are also discussed. Our findings will enable us to engineer the magneto-optical responses of matters via tuning the material parameters.
