Spectrum of electromagnetic excitations in a dc-biased semiconductor superlattice
Spectrum of electromagnetic excitations in a dc-biased semiconductor superlattice
复制标题
直流偏置半导体超晶格中的电磁激励频谱
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
H. Cui
中科院分区：
文献类型：
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作者：
A. Raspopin;A. Zharov;H. Cui
我们分析了微带线几何结构中直流偏置半导体超晶格中横向电磁激励的频谱和稳定性。我们表明存在一个临界直流电场强度，对应于平等的布洛赫频率和电子等离子体频率在底部的迷你带。在这个场强下，频率-波数频散曲线的性质发生了变化。对于亚临界直流场，电磁激励谱由传播的横向电磁波和准静态布洛赫振荡组成。在超临界直流场的情况下，横向电磁波和布洛赫振荡是混杂的。存在不稳定的低频分支，而高频分支总是稳定的。低频模式的不稳定性使得使用微带线和微腔器件创建基于布洛赫振荡器的可调谐太赫兹（THz）放大器和发生器成为可能。我们还发现低频分支...
We analyze the spectrum and stability of transverse electromagnetic excitations in a dc-biased semiconductor superlattice in a microstrip line geometry. We show the existence of a critical dc field strength that corresponds to equality of the Bloch frequency and the electron plasma frequency at the bottom of the miniband. At this field strength the frequency–wave-number dispersion curves change their character. For a subcritical dc field, the spectrum of electromagnetic excitations consists of propagating transverse electromagnetic wave and quasistatic Bloch oscillations. In the case of overcritical dc field, transverse electromagnetic wave and Bloch oscillations are hybridized. There is a low-frequency branch that is unstable, whereas the high-frequency one is always stable. Instability of the low-frequency mode makes possible the creation of a tunable Bloch-oscillator-based tetrahertz (THz) amplifier and generator using microstrip line and microcavity devices. We also find that the low-frequency branch ...