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Coulomb-renormalized intraband dynamics probed by THz emission

Coulomb-renormalisierte Intraband-Dynamik, gemessen mittels THz-Emission


Physica status solidi. B 204 (1997), No.31, pp.31-34 : Ill., Lit.
ISSN: 0031-8957
ISSN: 0370-1972
Journal Article
Fraunhofer IAF ()
III-V Halbleiter; III-V semiconductor; optical measurement; optische Messung; superlattice; Übergitter

THz emission from a narrow-miniband superlattice excited at its lower band edge reveals a hyperbolic bias dependence of the emission frequency. This reflects the emission from Coulomb-renormalized states, namely the anticrossing between the miniband exciton and the hh(-2) and hh(-l) Wannier-Stark-Ladder states visible in the interband absorption spectra. An analysis of the intraband and interband dephasing times, respectively. reveals that the intraband dynamics remains to be Coulomb-renormalized even after the dephasing of the interband coherence. This demonstrates that THz emission is dominated by long-lived excitionic contributions, in contrast to predictions at a Hartree-Fock level. The dynamics controlled truncation (DCT) approach taking into account the dynamics of the four-point correlation for the intraband current density is able to account for this experimental observation.