We propose and analyze a new multifunctional THz device that can operate as a tunable switch and a tunable filter. The device consists of a circular graphene nanodisk coupled to two nanoribbons oriented at 90° to each other. The graphene elements are placed on a dielectric substrate. The nanodisk is magnetized by a dc magnetic field normal to its plane. The physical principle of the device is based on the propagation of surface plasmon-polariton (SPP) waves in the graphene nanoribbons and excitation of dipole mode in the nanodisk resonator. Numerical simulations show that 0.61 T dc magnetic field provides transmission (regime ON) at the frequency 5.33 THz with the bandwidth (BW) 12.7% and filtering with a Q-factor of 7.8. At the central frequency, the insertion loss (IL) is around −2 dB, and the reflection coefficient is −43 dB. The regime OFF can be achieved by means of switching the dc magnetic field to zero value or by switching the chemical potential of the nanodisk to zero. This results in the ON/OFF ratio better than 20 dB. A small central frequency tuning of the switch by chemical potential is possible with a fixed dc magnetic field.

中文翻译：

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基于磁-电磁石墨烯纳米盘的可调谐太赫兹开关滤波器

我们提出并分析了一种新型的多功能太赫兹设备，它可以用作可调开关和可调滤波器。该设备包括一个圆形石墨烯纳米盘，该圆形盘与两个彼此成90°取向的纳米带相连。石墨烯元件被放置在介电衬底上。纳米磁盘被垂直于其平面的直流磁场磁化。该设备的物理原理是基于石墨烯纳米带中的表面等离振子-极化子（SPP）波的传播以及纳米盘谐振器中偶极子模式的激发。数值模拟表明，0.61 T dc磁场以5.33 THz的频率提供传输（状态ON），带宽（BW）为12.7％，并以7.8的Q因子进行滤波。在中心频率处，插入损耗（IL）约为-2 dB，反射系数为-43 dB。可以通过将直流磁场切换为零值或将纳米盘的化学势切换为零来实现OFF状态。这导致开/关比好于20 dB。在固定的直流磁场下，可以通过化学势对开关进行小的中心频率调谐。