Abstract

In the present theoretical analysis, we have demonstrated the magnetically tuned terahertz (THz) wave generation through the structure of hollow anharmonic horizontally aligned carbon nanotubes (HA-HA-CNTs) grown and embedded over the dielectric substrate under the effect of an externally applied transverse static electric field. Two transversely co-propagating amplitude-modulated (AM) filamented laser beams interact with this structure of HA-HA-CNTs under the combined effect of the externally applied static electric and magnetic fields, acting mutually perpendicular to each other as well as to the direction of propagation of the AM filamented laser beams. The novelty in our scheme is the use of non-uniform distribution of electrons in CNTs, whereas most of the research workers have chosen a uniform distribution of electrons in CNTs. Due to this, the restoration force experienced by the electrons of CNTs is not the same, but it becomes different for every electron of CNTs, and this results in anharmonicity. This anharmonicity in CNTs helps to broaden the resonance peak. The laser beams also exert the static and beat frequency nonlinear ponderomotive forces on the electrons of HA-HA-CNTs in such a way that the static nonlinear ponderomotive force is balanced by the pressure gradient force to form a transverse density ripple of zero frequency, whereas beat frequency nonlinear ponderomotive force is responsible for the THz generation through the HA-HA-CNTs. Nonlinear coupling between the drift velocity of the electrons and the density of electrons present in the plasma structure of HA-HA-CNTs results in the enhancement of THz generation. We have also found that the normalized THz field amplitude obtained at the resonance frequency point shows a significant enhancement with the increase of externally applied electric field in the steps of \({\text{5 kV cm}}^{ - 1}\) starting from \({5 }\) to \({\text{15 kV cm}}^{ - 1} ,\) and magnetic field in the steps of \({\text{5 kG}}\) \({\text{starting from 10 }}\) to \({\text{20 kG}}{.}\) The emitted THz radiations can be proved useful to detect bacterial and cell hydration states in the medical diagnosis.

中文翻译：

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在横向电场的作用下通过 HA-HA-CNT 进行磁调谐太赫兹辐射

摘要

在目前的理论分析中，我们证明了通过在外部施加的横向磁场的作用下生长并嵌入介电基板上的空心非谐波水平排列碳纳米管（HA-HA-CNT）结构来产生磁调谐太赫兹（THz）波。静电场。两束横向共同传播的调幅 (AM) 丝状激光束在外部施加的静电场和磁场的共同作用下与 HA-HA-CNT 的这种结构相互作用，作用方向相互垂直且垂直AM 丝状激光束的传播。我们方案的新颖之处在于使用了碳纳米管中电子的非均匀分布，而大多数研究人员选择了碳纳米管中电子的均匀分布。因此，碳纳米管的电子所受到的恢复力并不相同，而且对于碳纳米管的每个电子来说，恢复力都不同，这就导致了非谐性。碳纳米管的这种非谐性有助于展宽共振峰。激光束还对 HA-HA-CNT 的电子施加静态和拍频非线性有质动力，静态非线性有质动力与压力梯度力平衡，形成零频率的横向密度波纹，而拍频非线性有质动力负责通过 HA-HA-CNT 产生太赫兹。电子漂移速度与 HA-HA-CNT 等离子体结构中电子密度之间的非线性耦合导致太赫兹产生的增强。我们还发现，在谐振频率点获得的归一化太赫兹场幅度随着外加电场的增加而显着增强，步长为\({\text{5 kV cm}}^{ - 1}\)从\({5 }\)开始到\({\text{15 kV cm}}^{ - 1} ,\)，磁场以\({\text{5 kG}}\)为步长\( {\text{从 10 }}\)到\({\text{20 kG}}{.}\)发射的太赫兹辐射已被证明可用于检测医学诊断中的细菌和细胞水合状态。