AI 中文总结
该研究通过圆偏振脉冲在朗道量子化石墨烯中实现光诱导有效磁场，明确其微观起源与子晶格耦合无关，且其诱导的有效磁场强度优于典型电子起源逆法拉第效应，为相关狄拉克材料的磁光调控提供了清晰微观图像。
AI 中文摘要
圆偏振辐射触发的超快磁学是超快自旋控制的基础，与光自旋电子学、磁振子学等未来技术相关。该动力学通常因电子、自旋、声子、等离激元、拓扑和晶格等关联子系统在超快时间尺度下的多体量子耦合而变得复杂且相互交织。本文中，我们利用圆偏振脉冲在典型狄拉克材料石墨烯中，通过非等距朗道量子化态间的选择性激发，证明了光诱导有效磁场的存在。通过将朗道能级跃迁共振从其他低能激发中磁调谐开，我们获得了一个可通过静电调控的干净平台，并确定了光诱导磁信号的微观起源，该起源与子晶格耦合无关。由于不同朗道能级具有不同的光学霍尔电导率，通过光激发直接改变其布居数会产生具有色散磁场依赖性的瞬态法拉第旋转信号，反映了静态磁光线形。归一化到泵浦电场的诱导有效磁场超过了已报道的电子起源逆法拉第效应的典型值。我们的结果为电子起源的逆法拉第效应建立了清晰的微观图像，一旦在狄拉克系统及相关材料中，朗道能级跃迁被磁调谐至与其他低能激发重合，该效应可触发关联子晶格间的层级动力学。
英文摘要
Ultrafast magnetism triggered by circularly polarized radiation underpins ultrafast spin control, relevant to future technologies, e.g., opto-spintronics and magnonics. The dynamics are often complicated and intertwined among correlated subsystems, such as electrons, spins, phonons, plasmons, topology, and lattice, due to many-body quantum coupling at ultrafast timescales. Here, we demonstrate light-induced effective magnetic fields generated by selective excitation between non-equidistant Landau quantized states in graphene, a prototypical Dirac material, using circularly polarized pulses. By magnetically tuning the Landau-level transition resonance away from other low-energy excitations, we obtain a clean electrostatically controllable platform and identify the microscopic origin of the light-induced magnetic signals, independent of sublattice coupling. Because different Landau levels carry distinct optical Hall conductivities, direct modification of their occupancies via optical excitations creates transient Faraday rotation signals with dispersive magnetic-field dependence, mirroring the static magneto-optical lineshape. The induced effective magnetic field normalized by the pump electric field exceeds typical reported values for the inverse Faraday effect of electronic origin. Our results establish a clear microscopic picture of the inverse Faraday effect of electronic origin, which can trigger hierarchical dynamics among correlated sublattices once Landau-level transitions are magnetically tuned to coincide with other low-energy excitations in Dirac systems and related materials.
Comments23 pages, 4 figures
