Strong vibration nonlinearity in semiconductor-based nanomechanical systems
Strong vibration nonlinearity in semiconductor-based nanomechanical systems
复制标题
基于半导体的纳米机械系统中的强振动非线性
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
M. Dykman
中科院分区：
文献类型：
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作者：
K. Moskovtsev;M. Dykman
本文研究了电子-声子耦合对具有等效能谷的半导体纳米微机械系统振动本征模的影响。我们证明了这种耦合会导致强模态非线性。其机理是应变对谷简并的抬升。电子在山谷间的再分配是由电子-声子耦合常数与电子化学势或温度的很大比例控制的。我们发现电子自由能的应变项是四次的，它决定了模态频率的振幅依赖性。这种依赖性是针对硅微系统计算出来的。不同的模式和晶体取向会有显著的差异，并随电子密度和温度的变化而非单调变化。
We study the effect of the electron-phonon coupling on vibrational eigenmodes of nano- and micromechanical systems made of semiconductors with equivalent energy valleys. We show that the coupling can lead to a strong mode nonlinearity. The mechanism is the lifting of the valley degeneracy by the strain. The redistribution of the electrons between the valleys is controlled by a large ratio of the electron-phonon coupling constant to the electron chemical potential or temperature. We find the quartic in the strain terms in the electron free energy, which determine the amplitude dependence of the mode frequencies. This dependence is calculated for silicon microsystems. It is significantly different for different modes and the crystal orientation, and can vary nonmonotonously with the electron density and temperature.