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Title: Space- and time-dependent quantum dynamics of spatially indirect excitons in semiconductor heterostructures

We study the unitary propagation of a two-particle one-dimensional Schrödinger equation by means of the Split-Step Fourier method, to study the coherent evolution of a spatially indirect exciton (IX) in semiconductor heterostructures. The mutual Coulomb interaction of the electron-hole pair and the electrostatic potentials generated by external gates and acting on the two particles separately are taken into account exactly in the two-particle dynamics. As relevant examples, step/downhill and barrier/well potential profiles are considered. The space- and time-dependent evolutions during the scattering event as well as the asymptotic time behavior are analyzed. For typical parameters of GaAs-based devices, the transmission or reflection of the pair turns out to be a complex two-particle process, due to comparable and competing Coulomb, electrostatic, and kinetic energy scales. Depending on the intensity and anisotropy of the scattering potentials, the quantum evolution may result in excitation of the IX internal degrees of freedom, dissociation of the pair, or transmission in small periodic IX wavepackets due to dwelling of one particle in the barrier region. We discuss the occurrence of each process in the full parameter space of the scattering potentials and the relevance of our results for current excitronic technologies.
Authors:
;  [1] ;  [2] ;  [3]
  1. Department of Physics, Informatics and Mathematics, University of Modena and Reggio Emilia, Modena (Italy)
  2. (Italy)
  3. CNR-NANO S3, Institute for Nanoscience, Via Campi 213/a, 41125 Modena (Italy)
Publication Date:
OSTI Identifier:
22416022
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 142; Journal Issue: 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ANISOTROPY; ASYMPTOTIC SOLUTIONS; COMPARATIVE EVALUATIONS; COMPLEXES; DEGREES OF FREEDOM; DISSOCIATION; EXCITATION; EXCITONS; GALLIUM ARSENIDES; HOLES; PERIODICITY; POTENTIALS; REFLECTION; SCHROEDINGER EQUATION; SEMICONDUCTOR MATERIALS; TIME DEPENDENCE; WAVE PACKETS