標題: A novel energy filter using semiconductor superlattices and its application to tunneling time calculations
作者: Tung, HH
Lee, CP
電子工程學系及電子研究所
Department of Electronics Engineering and Institute of Electronics
公開日期: 1-十二月-1996
摘要: An artificial quantum-mechanical filter using superlattice structures is proposed in this paper, By gradually changing the barrier widths of a superlattice according to a Gaussian function, a broad-band and almost zero sidelobe transmission profile can be obtained. The WKB approximation is applied to demonstrate the phenomena of abrupt change of transmission profile, The proposed structure allows the incident electrons to be nearly totally transmitted when the impinging electron energy is in the passband, On the other hand, a complete reflection occurs when the impinging energy is in the stopband, By adjusting the structure parameters, the desired passband and stopband of such a filter can be obtained, Time evolution of an electron wavepacket moving through the structure is calculated by numerically solving the time-dependent Schrodinger equation, Numerical results clearly demonstrate the characteristics of total transmission and reflection, By simulating the movement of a totally transmitted wavepacket, ambiguity results from the nature of the wavepacket in the determination of electron tunneling time can be avoided. The generalized concept of matched quantum-mechanical wave impedance (QMWI) analogous to transmission line theory is presented to explaine the occurrence of total transmission of the proposed structure, The tunneling time (tau(QMWI)) calculated based on the concept of QMWI is compared with the accurate tunneling time obtained by our simulation.
URI: http://dx.doi.org/10.1109/3.544758
http://hdl.handle.net/11536/149377
ISSN: 0018-9197
DOI: 10.1109/3.544758
期刊: IEEE JOURNAL OF QUANTUM ELECTRONICS
Volume: 32
起始頁: 2122
結束頁: 2127
顯示於類別:期刊論文