Abstract

Selective high-order harmonic radiation can be generated when circularly polarized driving fields interact with single-walled carbon nanotubes. We obtain a gauge-covariant Hamiltonian for electrons confined to a nanotube surface in the presence of a circularly polarized electromagnetic field. Regularized delta-functions are used to approximate the \({\pi }\)-bonds in the nanotube unit cells, and the electron dynamics, in the presence of the field, is analyzed. The high harmonic radiation occurs for incident field intensities high enough to induce significant nonlinearities and chaos in the electron dynamics. Both (5, 5) and (10, 10) armchair nanotubes are considered and the electron quantum dynamics is modeled using Floquet–Bloch theory. The behavior of the quasienergy spectrum, Floquet states, and the electron current are described for varying intensities of the incident field. We show that, for incident radiation with frequency \({\omega }\), the emitted radiation for a (p, p) armchair nanotube will be \((2p\pm 1){\omega }\), \((4p\pm 1){\omega }\), etc.

Graphical abstract

中文翻译：

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碳纳米管产生的选择性高次谐波

摘要

当圆偏振驱动场与单壁碳纳米管相互作用时，会产生选择性的高次谐波辐射。对于存在圆极化电磁场的电子，我们获得了电子的规范协变哈密顿量。正则增量函数用于近似\（{\ pi} \）纳米管晶胞中的氢键结合，并在存在电场的情况下分析电子动力学。对于高到足以在电子动力学中引起明显的非线性和混沌的入射场强度，会发生高次谐波辐射。（5，5）和（10，10）扶手椅状纳米管均被考虑，并且使用Floquet-Bloch理论对电子量子动力学进行建模。描述了针对入射场强度变化的准能谱，浮子状态和电子电流的行为。我们表明，对于具有频率\（{\ omega} \）的入射辐射，（p，  p）扶手椅纳米管的发射辐射将为\（（2p \ pm 1）{\ omega} \），\（（ 4p \ pm 1）{\ omega} \）等。

图形概要