AI 中文总结
本研究在无偏置石墨烯及WSe₂/石墨烯异质结构中观测到ESR驱动的LPGE，建立微观理论解释其机制，证实光生伏打响应可作为ESR的探测手段。
AI 中文摘要
我们报道了无偏置单层石墨烯及WSe₂/石墨烯异质结构中电子自旋共振（ESR）驱动的线性光生伏特效應（LPGE）。在45-75 GHz线偏振辐射下，法拉第和沃伊特几何结构中的光电压均呈现显著的共振特征；在面外及面内磁场取向下，均观测到与石墨烯中电子自旋共振相关的多个共振峰，其磁场位置随频率线性变化，幅度在电荷中性点处反转符号，且共振贡献的符号与非共振德鲁德光生伏打背景相反。我们建立了微观理论，其中辐射诱导的动量对齐后经偏斜散射产生两种贡献，二者符号相反源于间接德鲁德吸收与直接自旋共振跃迁产生的正交动量对齐。该理论很好地描述了观测到的共振光电流的主要特征，为二维系统中ESR诱导的LPGE提供了微观描述，研究结果确立了光生伏打响应作为无偏置微米级石墨烯基器件中ESR的探测手段。
英文摘要
We report an electron-spin-resonance-driven linear photogalvanic effect (LPGE) in unbiased monolayer graphene and WSe_2/graphene heterostructures. Under linearly polarized 45--75 GHz radiation, the photovoltage exhibits pronounced resonant features in both Faraday and Voigt geometries. Multiple resonances associated with the electron spin resonance in graphene are observed for both out-of-plane and in-plane magnetic-field orientations. Their magnetic-field positions vary linearly with frequency, their amplitudes reverse sign across the charge-neutrality point, and the resonant contribution has the opposite sign to the nonresonant Drude photogalvanic background. We develop a microscopic theory in which radiation-induced momentum alignment followed by skew scattering generates both contributions. Their opposite signs originate from the orthogonal momentum alignments produced by indirect Drude absorption and direct spin-resonant transitions. The theory describes well the main features of the observed resonant photocurrent and provides a microscopic description of ESR-induced LPGE in two-dimensional systems. These results establish the photogalvanic response as a probe of ESR in unbiased micron-scale graphene-based devices.
Comments18 pages, 13 figures
