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Session M17 - DCMP: QUANTUM WELLS AND MESOSCOPIC TUNNELING
Mixed session, Thursday morning, March 23, 8:00
Room C3, San Jose Convention Center
\hyphenationFSQW The acoustic phonon confinement in a free standing quantum well (FSQW) results in an acoustic phonon energy quantization. The characteristic quantization energy is about 1 meV what corresponds to 0.25 THz (for GaAs FSQW of width 100\,Å Free electrons may absorb electromagnetic waves in this frequency range if they emit or absorb acoustic phonons. Therefore, the terahertz range absorption will reveal the peculiarities of the acoustic phonon spectrum in mesoscopic structures. We have calculated the absorption coefficient of GaAs FSQW of width 100\,Åat low lattice temperature in the frequency range 0.1-1 THz , solving the kinetic equation for the one-particle density matrix. We took into account a time dependent electric field and electron interactions with dilatational phonons through the deformation potential. The second derivative of the absorption coefficient over frequency exhibits several maxima at frequencies of the lowest acoustic phonon modes. These maxima occur due absorption of photons by electrons which is accompanied by emission of corresponding acoustic phonons.