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arXiv 1607.01332cond-mat.mes-hall
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核/壳Ge/Si和Si/Ge纳米线中的电声声子相互作用

Electron-acoustic-phonon interaction in core/shell Ge/Si and Si/Ge nanowires

Darío G. Santiago-Pérez, C. Trallero-Giner, G. E. Marques

摘要:

推导了具有圆形截面的Ge/Si和Si/Ge核/壳纳米线结构的电子-和空穴-声学-声子形变势哈密顿量(H_{E-DP})的一般表达式.基于短程弹性连续介质方法和导出的解析结果,分析了空间约束对矢量声子位移、声子色散关系以及电子-声子和空穴-声子散射振幅的影响.结果表明,声学矢量位移,声子频率和H_{E-DP}目前混合扭转,轴向和径向分量取决于角动量量子数和声子波矢量的考虑。结果表明,由于界面处的空间约束和本征应变,各组分材料的体群速度被重正化。讨论了绝缘壳层对Ge/Si和Si/Ge纳米线中声子色散和电声子耦合的影响。

英文摘要:

General expressions for the electron- and hole-acoustical-phonon deformation potential Hamiltonian (H_{E-DP}) are derived for the case of Ge/Si and Si/Ge core/shell nanowire structures (NWs) with circular cross section. Based on the short-range elastic continuum approach and on derived analytical results, the spatial confined effects on the vector phonon displacement, the phonon dispersion relation and the electron- and hole-phonon scattering amplitudes are analyzed. It is shown that the acoustical vector displacement, phonon frequencies and H_{E-DP} present mixed torsional, axial, and radial components depending on the angular momentum quantum number and phonon wavector under consideration. The treatment shows that bulk group velocities of the constituent materials are renormalized due to the spatial confinement and intrinsic strain at the interface. The role of insulating shell on the phonon dispersion and electron-phonon coupling in Ge/Si and Si/Ge NWs are discussed.

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