Resonant states induced by impurities in heterostructures
Resonant states induced by impurities in heterostructures
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异质结构中的杂质引起的共振态
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
K. Chao
中科院分区：
文献类型：
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作者：
A. Blom;M. Odnoblyudov;I. Yassievich;K. Chao
研究了异质结构量子威尔斯阱外杂质诱导导带共振态的形成。我们推导出捕获和散射振幅，共振位置和宽度的一般表达式，我们还计算了量子阱中的能谱和态密度的影响。该理论被应用到两个典型的杂质势，深能级的零程势和库仑势。结果表明，在较宽的能量区间内，态密度的扰动是显著的，并且共振位置随调制掺杂距离的变化呈现非单调性.共振宽度随距离呈指数衰减，但当我们接近量子阱界面时，共振宽度与能带不连续性处于同一量级。捕获和散射系数可能在狭窄的能量间隔内变化几个数量级，产生明显且强烈的散射机制。
A study of the formation of resonant states in the conduction band, induced by impurities outside heterostructure quantum wells, is presented. We derive general expressions for the capture and scattering amplitudes, the resonance position and width, and we also calculate the effect on the energy spectrum and the density of states in the quantum well. The theory is applied to two typical impurity potentials, the zero-range potential of deep levels and the Coulomb potential. It is found that the perturbation of the density of states can be significant over wide energy intervals, and that the resonance position may behave nonmonotonically with the modulation-doping distance. The resonance width decays exponentially with the distance, but becomes of the same order as the band discontinuity as we approach close to the quantum well interface. The capture and scattering coefficients may vary by several orders of magnitude over narrow energy intervals, producing a pronounced and strong scattering mechanism.