共查询到17条相似文献,搜索用时 250 毫秒
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反比相关的双曲余弦平方势与电子的面沟道辐射 总被引:5,自引:4,他引:1
带电粒子在晶体沟道中的运动行为决定于粒子-晶体相互作用势.常用的粒子晶体相互作用势有Lindhard势、Moliere和正弦平方势.当超相对论电子沿着晶体的低晶面指数方向入射时,电子和晶体之间的相互作用势可用反比相关的双曲余弦平方势描写.在量子力学框架内,利用这一相互作用势成功地将系统的Schrodinger方程化为超几何方程,从而简化了系统本征值和本征态问题的计算和讨论.考虑到质量的相对论效应和频率的Doppler效应,导出了实验室坐标系中电子的能级分布和辐射谱分布.并以电子的Si(110)面沟道辐射为例,选定一组与入射粒子有关的参数和一组与晶体有关的参数,计算了能量为E=0.5GeV的电子在低位能级之间的跃迁,导出了电子面沟道辐射能量ΔE=49.1MeV,得到了与实验符合的结果. 相似文献
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本文采用一种新的变分波函数描述GaAs/Ga1-xAlxAs窄量子阱中的浅施主基态,并计算了杂质基态波函数和结合能。计算所得数值结果表明正确考虑窄量子阱与杂质势间的耦合作用是极为重要的。
关键词: 相似文献
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从理论上研究了电子-声子相互作用对正切平方量子阱中光吸收系数的影响,首先利用微扰论方法求出考虑极化子效应时正切平方量子阱的波函数和能级,然后利用密度矩阵算符理论和迭代法得到光吸收系数的解析表达式,最后以典型的GaAs/AlGaAs正切平方量子阱为例进行数值计算。结果表明,极化子效应对线性吸收系数、三阶非线性吸收系数和总吸收系数都有显著的影响,在相同光强的情况下极化子效应使光饱和吸收现象更加明显;考虑电声相互作用后,总吸收系数的改变量随着势阱宽度b的减小和势阱深度V0的增加而增大。 相似文献
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采用数值计算方法分析了GaAs/Ga1-xAlxAs 半导体量子阱的光 辐射-热离子制冷. 以漂移-扩散模型为基础,通过电流连续性方程和泊松方程自洽地计算出在外加正向偏压的 条件下半导体内部的载流子分布情况,并在此基础上计算了阱内载流子的发光复合和俄歇复 合,从而确定了半导体异质结量子阱光辐射-热离子制冷的最优条件.进一步分析了不同Al组 分的Ga1-xAlxAs材料以及不同的掺杂浓度对制冷效果的影响, 为该领域的实验工作提供了极有价值的参考.
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半导体异质结
光辐射
制冷 相似文献
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假设超晶格量子阱是一个形状任意的周期势阱,电子在超晶格中的运动问题可视为周期场中的运动问题.在量子力学的框架内,从Schr dinger方程和它的一般解出发,利用Bloch理论和传输矩阵方法导出了系统的色散方程;在抛物线近似下,讨论了超晶格量子阱的电子跃迁.结果表明,辐射能量位于红外、远红外或太赫兹波段. 相似文献
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K. S. Teng M. Brown A. Kestle P. Smowton P. Blood S. Pinches P. A. Mawby S. P. Wilks 《Applied Surface Science》2002,190(1-4):284-287
In this paper, we present a critical study of a multi-quantum barrier (MQB) structure fabricated using the Al0.5In0.5P/Ga0.5In0.5P material system. The structure was optimised theoretically based on a single Γ band model. When an identical structure was placed in a quantum well laser device, no improvement in the threshold current was observed compared to QW laser structure without an MQB. Cross-sectional scanning tunnelling microscopy (STM) was used to assess the structural quality of the MQB structure for the first time. Factors affecting the limited barrier enhancement are discussed in terms of the interfacial quality of the Al0.5In0.5P/Ga0.5In0.5P interface in the superlattice of the MQB and the need to consider multi-valley transport. The paper highlights some of the fundamental problems that must be overcome for MQBs to be a viable method to improve red laser efficiency. 相似文献
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Recursion formulae for the reflection and the transmission probability amplitudes and the eigenvalue equation for multistep potential structures are derived. Using the recursion relations, a dispersion equation for periodic potential structures is presented. Some numerical results for the transmission probability of a double barrier structure with scattering centers, the lifetime of the quasi-bound state in a single quantum well with an applied field, and the miniband of a periodic potential structure are presented. 相似文献
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The problem of the polaron spectrum is studied in a superlattice having narrow quantum wells and relatively wide potential barriers. A δ-like superlattice potential is chosen to solve the problem. This model is adequate, if the penetration depth of the electron wave function into the barrier region is much greater than the width of the quantum well. A weak-coupling polaron at low temperature is studied. Only volume phonons are considered. Expressions are obtained for the polaron mass and the shift of the polaron energy under these assumptions. To test the model, numerical calculations were performed for an InAs-GaSb superlattice, whose quantum wells are quite deep (the energy offset of the conduction bands in InAs and GaSb equals 830 meV), narrow (the width of a quantum well corresponds to the width of an InAs monolayer 6 Å), and the barrier width corresponding to the thickness of the GaSb layers equals 150 Å. The assumption that the penetration depth of the wave function is much greater than the barrier width holds well. 相似文献
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Solving ground eigenvalue and eigenfunction of spheroidal wave equation at low frequency by supersymmetric quantum mechanics method 下载免费PDF全文
The spheroidal wave functions are found to have extensive applications in many branches of physics and mathematics. We use the perturbation method in supersymmetric quantum mechanics to obtain the analytic ground eigenvalue and the ground eigenfunction of the angular spheroidal wave equation at low frequency in a series form. Using this approach, the numerical determinations of the ground eigenvalue and the ground eigenfunction for small complex frequencies are also obtained. 相似文献
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The shot noise properties in a graphene-based multi-quantum well structure are investigated theoretically. It is found that when the number of the potential barriers (quantum wells) is big enough and the width of the barriers and the wells is shorter than the mean free path, another Dirac-like point at which the Fermi energy equals half of the barrier height appears. The transport is almost forbidden at this new Dirac-like point, the conductivity gets the minimum, and the Fano factor approaches 1/3. With the random potential barrier being taken into consideration, the conductance enhances clearly, meanwhile the Fano factor is suppressed much more. 相似文献
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