This paper proposes a theoretical model of photo-controlled quantum capacitors in double-gated graphene-insulator-graphene (DGGIG) structure for terahertz (THz) frequency and phase modulations. In the model, the current-voltage characteristics of each segment of the DGGIG structure are controlled by different gate voltages. Using the different voltages, the DGGIG structure can be used to either generate plasma oscillation waves or shift phase in the terahertz band. Not only has the DGGIG structure various electrical properties, but also the optical properties are also excellent. Photoexcitation alters carrier concentration in DGGIG channel, and thus causes the change of the quantum capacitors. We propose a photo-controlled quantum capacitor model to quantify this phenomenon. The model shows that the quantum capacitors and photoexcitation have a sublinear dependence. An example of a device based on the model is given to describe the application of photo-controlled quantum capacitors in terahertz frequency and phase modulations. The modelled device shows that photoexcitation can change the frequency and phase of the plasma oscillation waves.

中文翻译：

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用于太赫兹频率和相位调制的栅极石墨烯-绝缘体-石墨烯中的光控量子电容器

本文提出了一种用于太赫兹 (THz) 频率和相位调制的双门控石墨烯-绝缘体-石墨烯 (DGGIG) 结构中光控量子电容器的理论模型。在模型中，DGGIG结构各段的电流-电压特性由不同的栅极电压控制。使用不同的电压，DGGIG 结构可用于生成等离子体振荡波或在太赫兹波段中移动相位。DGGIG结构不仅具有各种电性能，而且光学性能也非常出色。光激发改变 DGGIG 通道中的载流子浓度，从而引起量子电容器的变化。我们提出了一种光控量子电容器模型来量化这种现象。该模型表明量子电容器和光激发具有次线性相关性。给出了基于该模型的器件示例，描述了光控量子电容器在太赫兹频率和相位调制中的应用。模拟装置表明光激发可以改变等离子体振荡波的频率和相位。