Title :
How different is quantum kinetics from a Raman-process?
Author :
Hugel ; Wegener, Martin ; Vu ; Banyai ; Haug, H. ; Tinjod ; Mariette, Henri
Author_Institution :
Inst. fur Angewandte Phys., Karlsruhe Univ., Germany
Abstract :
Summary form only given. In this work, we study a case in which the oscillation frequency is larger than the bare phonon frequency by a factor of about five. We study the quantum kinetics of holes coupled to LO-phonons. In GaAs this was not possible because in GaAs an oscillation period around 10 fs would result which is not detectable with 10 fs pulses. In CdTe, the parameters are much more favorable. Naively, one would use /spl omega//sub osc/ = /spl omega//sub LO/ (1+m/sub hh//m/sub e/), however, microscopic theory suggests that effects beyond weak coupling and the influence of the electron dynamics modify this formula leading to 42 fs oscillation period, much shorter than the well-known 195 fs period of the CdTe LO-phonon. Nevertheless, in the theory, the oscillation does get faster with increasing mass ratio m/sub hh//m/sub e/ - a clear signature of hole quantum kinetics.
Keywords :
II-VI semiconductors; Raman spectra; cadmium compounds; electron-phonon interactions; high-speed optical techniques; photon echo; semiconductor epitaxial layers; 195 fs; 42 fs; CdTe; CdTe epitaxial thin film; Raman process; ZnTe; ZnTe substrate; bare phonon frequency; electron dynamics; hole LO-phonon coupling; hole quantum kinetics; optically excited carrier densities; oscillation frequency; oscillation period; photon echo experiments; Cadmium compounds; Electrons; Phonons; Raman scattering; Semiconductor epitaxial layers; Ultrafast optics;
Conference_Titel :
Quantum Electronics and Laser Science Conference, 2002. QELS '02. Technical Digest. Summaries of Papers Presented at the
Conference_Location :
Long Beach, CA, USA
Print_ISBN :
1-55752-708-3
DOI :
10.1109/QELS.2002.1031409