Point-contact spectroscopy of electron-phonon interaction in normal-metal single crystals
Point-contact spectroscopy of electron-phonon interaction in normal-metal single crystals
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普通金属单晶中电子-声子相互作用的点接触光谱
DOI：
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
A. Batrak
中科院分区：
文献类型：
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作者：
I. Yanson;I. O. Kulik;A. Batrak
本文综述了近年来用点接触光谱法（PCS）研究金属声子谱的情况，特别强调了研究单晶中电子-声子相互作用的可能性。讨论了接触中的电流流动的各种制度，包括弹道，扩散和热制度。前者（克努森极限）被证明是最合适的光谱的目的; PC光谱（导数d2 V/dI 2）在这种情况下揭示了一个复杂的结构包含的信息奇异点的声子态密度以及各向异性（和能量依赖性）的矩阵元素的电子-声子相互作用。实验结果为铜，最合适的金属获得足够好的质量接触。分析了高能PC谱背景和低能PC谱奇异性的来源。这是由于非平衡声子在结中的重吸收，以及电子-杂质散射对电子-声子碰撞效率的影响。
Recent studies of the phonon spectra of metals using “point-contact spectroscopy” (PCS) are reviewed, with particular emphasis on the possibility of studying the electron-phonon interaction in single crystals. Various regimes of current flow in contacts are discussed, including ballistic, diffusion, and thermal regimes. The former (the Knudsen limit) proves to be the most appropriate for spectroscopic purposes; the PC spectrum (the derivative d2V/dI2)in this case reveals a complicated structure containing information about singular points of the phonon density of states as well as the anisotropy (and energy dependence) of matrix elements of the electron-phonon interaction. Experimental results are presented for Cu, the most suitable metal for obtaining contacts of sufficiently good quality. The origins of the PC spectrum background at high energies and the singularities of PC spectra at low energy are analyzed. They are attributed to the nonequilibrium phonons reabsorbed in the junction, and to the influence of electron-impurity scattering upon the effectiveness of electron-phonon collisions.