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Quantum Kinetics of Intra‐ and Intersubband Coulomb Dynamics in Quantum Wires
Author(s) -
Prengel F.,
Schöll E.,
Kuhn T.
Publication year - 1997
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/1521-3951(199711)204:1<322::aid-pssb322>3.0.co;2-e
Subject(s) - semiclassical physics , density matrix , physics , excitation , quantum , quantum wire , coulomb , electron , ionization , kinetic energy , condensed matter physics , principal quantum number , scattering , atomic physics , quantum mechanics , quantum dissipation , ion
The Coulomb dynamics of electrons in the conduction subbands of a quantum wire is studied in a multi‐subband density matrix approach. The hierarchy of equations of motion for the density matrices is expressed in terms of many‐particle density correlations and truncated by retaining only the one‐particle density matrix and the two‐particle density correlations. Based on this, quantum kinetic simulations for a rectangular wire have been performed for carriers which are generated optically in the lower subband of a two‐subband system. The time‐dependent broadening of Coulomb scattering induced transitions due to quantum‐mechanical energy–time uncertainty strongly influences both intra‐ and intersubband processes. It is explained why the quantum kinetic intersubband impact ionization rate is smaller than the semiclassical one for excitation above the semiclassical impact ionization threshold, but considerably larger for excitation below that threshold.