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51.
In this paper, a model to calculate the dark current of quantum well infrared photodetectors at high-temperature regime is presented. The model is derived from a positive-definite quantum probability-flux and considers thermionic emission and thermally-assisted tunnelling as mechanisms of dark current generation. Its main input data are the wave functions obtained by time-independent Schrodinger equation and it does not require empirical parameters related to the transport of carriers. By means of this model, the dark current of quantum well infrared photodetectors at high-temperature regime is investigated with respect to the temperature, the barrier width, the applied electric field and the position of the first excited state. The theoretical results are compared with experimental data obtained from lattice-matched InAlAs/InGaAs, InGaAsP/InP on InP substrate and AlGaAs/GaAs structures with rectangular wells and symmetric barriers, whose absorption peak wavelengths range from MWIR to VLWIR. The corresponding results are in a good agreement with experimental data at different temperatures and at a wide range of applied electric field. 相似文献
52.
借助于球调和多项式的de la Vallée Poussin和构造出了单位球面S^q上一类带形平移网络算子,并给出了其对L^p(S^q)中函数一致逼近的收敛速度.
相似文献
53.
In this Letter we develop a general procedure leading from a Mourre-type estimation for a given self-adjoint operator H to a Hardy-type weighted inequality. We use this method in order to prove exponential decay for eigenvectors of a large class of perturbations of operators of convolution with bounded analytic functions. 相似文献
54.
通过引入经验覆盖数(empirical covering number)和投影算子(projection-operator),从理论上研究正则化最小二乘回归学习算法.与已有的方法相比,一方面简化了回归分析的过程;另一方面,提高了最小二则回归学习算法的误差收敛阶.即,通过引入投影算子,得到了O(m-1)型的收敛阶,这是统计学习理论中关于泛化误差的最佳逼近阶. 相似文献
55.
56.
L. Shao D. Shao C. G. Shao H. Noda 《International Journal of Theoretical Physics》2008,47(6):1663-1691
Using the recoupling theorem and graph calculation in loop quantum gravity, it is demonstrated that the action of metric matrix
operator on Gaussian weave state is an eigenaction, the representation matrix elements of the metric operator and their expectation
values are calculated. The values of length of tangent vectors of edges adjacent to the vertex of Gaussian weave state, as
well as the angles between them are also obtained in the cases of k=0 and k=2. 相似文献
57.
58.
59.
FAN Hong-Yi GUO Qin 《理论物理通讯》2008,49(4):859-862
We introduce the quantum Hadamard operator in continuum state vector space and find that it can be decomposed into a single-mode squeezing operator and a position-momentum mutual transform operator. The two-mode Hadamard operator in bipartite entangled state representation is also introduced, which involves the two-mode squeezing operator and [η〉 ←→|ξ〉 mutual transformation operator, where [η〉 and |ξ〉 are mutual conjugate entangled states. All the discussions are proceeded by virtue of the IWOP technique. 相似文献
60.
The q-p phase-space distribution function is a popular tool to
study semiclassical physics and to describe the quantum aspects of a system. In this paper by using the pure state density operator formula of the Husimi operator
Δh(q,p;κ)=|p,q〉κκ〈p,q| we deduce the Husimi function of the excited squeezed vacuum state. Then we study the behavior of Husimi distribution graphically. 相似文献