A weakly coupled semiconductor superlattice as a harmonic hypersonic-electrical transducer
A weakly coupled semiconductor superlattice as a harmonic hypersonic-electrical transducer
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DOI：
10.1088/1367-2630/17/8/083064
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发表时间：
2015-09
影响因子：
3.3
通讯作者：
C. Poyser;A. Akimov;A. Balanov;R. Campion;A. Kent
中科院分区：
文献类型：
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作者：
C. Poyser;A. Akimov;A. Balanov;R. Campion;A. Kent
从实验和理论上研究了高频应变脉冲串对弱耦合半导体超晶格中电荷输运的影响。在100 GHz量级的频率范围内，这种激励可视为单次谐波高超声速激励。高超声速波包在沿SL轴行进时，会影响电子的隧穿，从而控制流过器件的电流。我们揭示了电流的变化如何依赖于高超声速激发的参数和施加到超晶格上的偏置。我们发现，声激励引起的超晶格输运性质的变化可以很大程度上用未扰动系统的电流-电压关系来解释。我们的实验测量表明，转移电荷与应变脉冲的重复频率有关，存在多个峰值。我们证明，在考虑了作为高超声速激励发生器的金属薄膜中的多次反射后，这些共振可以用外加声学微扰的频谱来理解。我们的研究结果表明，半导体超晶格可以作为高超声速换能器应用于各种微波器件。
We study experimentally and theoretically the effects of high-frequency strain pulse trains on the charge transport in a weakly coupled semiconductor superlattice. In a frequency range of the order of 100 GHz such excitation may be considered as single harmonic hypersonic excitation. While travelling along the axis of the SL, the hypersonic acoustic wavepacket affects the electron tunnelling, and thus governs the electrical current through the device. We reveal how the change of current depends on the parameters of the hypersonic excitation and on the bias applied to the superlattice. We have found that the changes in the transport properties of the superlattices caused by the acoustic excitation can be largely explained using the current–voltage relation of the unperturbed system. Our experimental measurements show multiple peaks in the dependence of the transferred charge on the repetition rate of the strain pulses in the train. We demonstrate that these resonances can be understood in terms of the spectrum of the applied acoustic perturbation after taking into account the multiple reflections in the metal film serving as a generator of hypersonic excitation. Our findings suggest an application of the semiconductor superlattice as a hypersonic-electrical transducer, which can be used in various microwave devices.