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

Journal Article · Wed Jan 21 00:00:00 EST 2015 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4905483· OSTI ID:22416022

Grasselli, Federico; Goldoni, Guido ^[1]; Bertoni, Andrea ^[2]

---

1. Department of Physics, Informatics and Mathematics, University of Modena and Reggio Emilia, Modena (Italy)
2. CNR-NANO S3, Institute for Nanoscience, Via Campi 213/a, 41125 Modena (Italy)

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.

• OSTI ID: 22416022
• Journal Information: Journal of Chemical Physics, Vol. 142, Issue 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

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