Markovian and Non-Markovian Light-Emission Channels in Strained Quantum Wires
| Autor: | Franklin M. Matinaga, L. Villegas-Lelovsky, M. Rebello Sousa Dias, E. Ribeiro, J. C. González, Gilmar E. Marques, Victor Lopez-Richard, C. Trallero-Giner |
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| Rok vydání: | 2009 |
| Předmět: |
Photoluminescence
Surface Properties Phonon Physics::Optics Bioengineering Electronic structure Condensed Matter::Materials Science Materials Testing Fiber Optic Technology General Materials Science Particle Size Quantum Optical Fibers Condensed matter physics Nanowires Chemistry Mechanical Engineering Relaxation (NMR) Resonance Optical polarization General Chemistry Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Condensed Matter Physics Markov Chains Semiconductors Quantum Theory Light emission |
| Zdroj: | Nano Letters. 9:3129-3136 |
| ISSN: | 1530-6992 1530-6984 |
| DOI: | 10.1021/nl9012024 |
| Popis: | We have achieved conditions to obtain optical memory effects in semiconductor nanostructures. The system is based on strained InP quantum wires where the tuning of the heavy-light valence band splitting has allowed the existence of two independent optical channels with correlated and uncorrelated excitation and light-emission processes. The presence of an optical channel that preserves the excitation memory is unambiguously corroborated by photoluminescence measurements of free-standing quantum wires under different configurations of the incoming and outgoing light polarizations in various samples. High-resolution transmission electron microscopy and electron diffraction indicate the presence of strain effects in the optical response. By using this effect and under certain growth conditions, we have shown that the optical recombination is mediated by relaxation processes with different natures: one a Markov and another with a non-Markovian signature. Resonance intersubband light-heavy hole transitions assisted by optical phonons provide the desired mechanism for the correlated non-Markovian carrier relaxation process. A multiband calculation for strained InP quantum wires was developed to account for the description of the character of the valence band states and gives quantitative support for light hole-heavy hole transitions assisted by optical phonons. |
| Databáze: | OpenAIRE |
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