论文标题
磁化旋转轨道耦合石墨烯中可控的非倒数光学响应和交接性转换
Controllable nonreciprocal optical response and handedness-switching in magnetized spin orbit coupled graphene
论文作者
论文摘要
从低能有效的哈密顿模型开始,我们从理论上计算了具有Rashba旋转轨道偶联(SOC)的磁化石墨烯层的动力学电导率和介电常数张量。我们的结果揭示了横向霍尔电导率与通常的非近环纵向电导率相关。进一步的分析表明,对于中间磁化强度,可以通过在动力学光学响应(纵向和横向成分)中通过两个良好分离的峰在实验中识别磁化和SOC的相对幅度作为光子频率的函数。此外,对于广泛的化学电位和磁化强度,获得了频率依赖性介电常数张量。采用实验逼真的参数值,我们计算了由磁化旋转轨道耦合石墨烯和介电绝缘子层组成的代表性设备的圆形二色性,并由金属板支持。结果表明,对于右撇子和左撇子偏振电磁波,该设备具有不同的相对吸收性。发现磁化的旋转轨道耦合石墨烯支持强度交换的强度,从而有效控制了相对于SOC强度的化学势和磁化强度。
Starting from a low-energy effective Hamiltonian model, we theoretically calculate the dynamical optical conductivity and permittivity tensor of a magnetized graphene layer with Rashba spin orbit coupling (SOC). Our results reveal a transverse Hall conductivity correlated with the usual nonreciprocal longitudinal conductivity. Further analysis illustrates that for intermediate magnetization strengths, the relative magnitudes of the magnetization and SOC can be identified experimentally by two well-separated peaks in the dynamical optical response (both the longitudinal and transverse components) as a function of photon frequency. Moreover, the frequency dependent permittivity tensor is obtained for a wide range of chemical potentials and magnetization strengths. Employing experimentally realistic parameter values, we calculate the circular dichroism of a representative device consisting of magnetized spin orbit coupled graphene and a dielectric insulator layer, backed by a metallic plate. The results reveal that this device has different relative absorptivities for right-handed and left-handed circularly polarized electromagnetic waves. It is found that the magnetized spin orbit coupled graphene supports strong handedness-switchings, effectively controlled by varying the chemical potential and magnetization strength with respect to the SOC strength.