Münster 1999 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 23: Poster II
HL 23.53: Poster
Mittwoch, 24. März 1999, 14:00–18:00, Z
Parametric amplification and generation of terahertz-wave radiation in arrays of quantum dots and wires. — •S.A. Mikhailov — Max-Planck Institut für Physik komplexer Systeme, Dresden.
I calculate a magneto-optical response of a parabolic quantum dot (wire) to a uniform (dipole) and non-uniform (quadrupole) time-dependent external electric fields. Effects of electron-electron interactions are taken into account exactly. I show that, under certain conditions (the frequency Ω of the quadrupole signal is about twice the frequency of the dipole radiation ω), the array of quantum dots (wires) can amplify/radiate the dipole radiation at ω≃ω0, due to a parametric resonance occuring in the system. Here ω0(B) is the dipole-resonance frequency of the dots (wires) and B is the magnetic field. I propose a specific structure [quantum dot (wire) array with a complex elementary cell] which may generate (amplify) a coherent far-infrared radiation at ω≃ω0 being pumped by a non-coherent radiation with a higher frequency. I calculate the threshold power of the proposed amplifier (oscillator). For a nanoscale device the operating frequency can be chosen in the range from ≃ 0.3 THz up to a few THz, and the threshold power of generation (at liquid He temperatures) is below 1 mW/cm2.