Dresden 2006 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 50: Poster II
HL 50.37: Poster
Donnerstag, 30. März 2006, 16:30–19:00, P3
Fine structure of the intersubband absorption in stepped quantum wells — •Pilar Aceituno1, Antonio Hernández-Cabrera1, and Fedir T. Vasko2 — 1Departamento de Física Básica, Universidad de La Laguna,La Laguna 38206-Tenerife, Spain — 2Institute of Semiconductor Physics, NAS of Ukraine, Kiev, 252650, Ukraine
The relative intersubband infrared absorption (IIRA) of stepped quantum wells (SQWs) of GaAs-GaAlAs, when subjected to an intense THz irradiation, is theoretically studied. By using the matrix density formalism, together with the adiabatic and resonant approximations, we obtain analytical expressions for the IIRA. When the pump intensity is of the order of megawatts, it is found that the absorption peak splits in a set of satellites (fine structure) due to (n+1) order intersubband transitions with the contribution of (n) THz photons and one IR photon. The number of peaks depends on the width of the SQW and the THz field intensity. Moreover, it is also found a strong modification of the absorption, which consists on a noticeable broadening of the zero-field peak and a shift towards higher energy values. We have used in calculations multiple SQW structures formed by 10 decoupled SQWs because the IIRA is usually too weak to be detected in a single QW.
A. Hernández-Cabrera, P. Aceituno, and F.T. Vasko, Phys. Rev. B, 72 045307 (2005).
Acknowledgment: This work was supported in part by Ministerio de Educación y Ciencia (Spain) and FEDER, under the project FIS2005-01672.