Hole-spin initialization and relaxation times in InAs/GaAs quantum dots
| Autor: | B. Eble, Frédéric Bernardot, Pascal Desfonds, F. Fras, Christophe Testelin, Maria Chamarro, Audrey Miard, Aristide Lemaître |
|---|---|
| Přispěvatelé: | Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2011 |
| Předmět: |
III-V semiconductors
Dephasing 02 engineering and technology Spin relaxation and scattering 01 natural sciences [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph] 0103 physical sciences Time domain 010306 general physics Spectroscopy Spin-½ Physics Condensed matter physics Quantum dots Relaxation (NMR) Order (ring theory) spin initialization 021001 nanoscience & nanotechnology Condensed Matter Physics Optical creation of spin polarized carriers hyperfine interaction Electronic Optical and Magnetic Materials Magnetic field Quantum dot Atomic physics 0210 nano-technology |
| Zdroj: | Physical Review B: Condensed Matter and Materials Physics (1998-2015) Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2011, 84, pp.125431. ⟨10.1103/PHYSREVB.84.125431⟩ Physical Review B: Condensed Matter and Materials Physics (1998-2015), American Physical Society, 2011, 84, pp.125431. ⟨10.1103/PHYSREVB.84.125431⟩ |
| ISSN: | 1550-235X 1098-0121 |
| DOI: | 10.1103/physrevb.84.125431 |
| Popis: | We study, at low temperature and zero magnetic field, the hole-spin dynamics in InAs/GaAs quantum dots. We measure the hole-spin relaxation time at a time scale longer than the dephasing time (about ten nanoseconds), imposed by the hole-nuclear hyperfine coupling. We use a pump-probe configuration and compare two experimental techniques based on differential absorption. The first one works in the time domain, and the second one is a new experimental method, the dark-bright time-scanning spectroscopy (DTS), working in the frequency domain. The measured hole-spin relaxation times, using these two techniques, are very similar, in the order of ${T}_{N}^{h}\ensuremath{\approx}$1 \ensuremath{\mu}s. It is mainly imposed by the inhomogeneous hole hyperfine coupling in the hole localization volume. The DTS technique allows us also to measure the hole-spin initialization time ${\ensuremath{\tau}}_{i}$. The hole spin is initialized by a periodic train of circularly polarized pulses at 76 MHz; we have observed that ${\ensuremath{\tau}}_{i}$ decreases as the power density increases, and we have measured a minimum value of ${\ensuremath{\tau}}_{i}\ensuremath{\approx}$100 ns in good agreement with a simple model [see B. Eble, P. Desfonds, F. Fras, F. Bernardot, C. Testelin, M. Chamarro, A. Miard, and A. Lema\^{\i}tre, Phys. Rev. B 81, 045322 (2010)]. |
| Databáze: | OpenAIRE |
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