Electrical Manipulation of Spin Injection into a Single InAs Quantum Dots

We demonstrate electrical spin‐injection into a single InAs quantum dot embedded in a GaAs‐based p–i–n diode structure using a diluted magnetic semiconductor (ZnMnSe) as a spin‐source. The spin‐information can be extracted directly by evaluating the polarisation degree of the single quantum dot electroluminescence signal. We obtain a spin‐polarisation up to 100% at T = 5 K that is decreasing with higher temperature. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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“…By applying external voltages, spin-polarized carriers from the spin-aligner can be transferred into the QDs [10,11].…”

Section: Sample Design and Experimentsmentioning

confidence: 99%

Electrical injection of spin‐polarized electrons into single quantum dots

Kümmell

Arians

Huang

et al. 2009

Physica Status Solidi (b)

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“…The zero dimensional character of QDs results in the quantization of the electronic orbital states, which significantly suppresses many spin flip mechanisms and leads to long spin-relaxation times 2 . This effect has been seen in several experiments including electrical spin injection into self assembled InGaAs QDs using ferromagnetic GaMnAs, paramagnetic ZnMnSe and ZnBeMnSe layers, as well as ferromagnetic metal contacts [3][4][5][6][7][8][9][10][11][12] . Room temperature electrical spin pumping has also been achieved 10 and it has been attributed to the suppression of the Dyakonov-Perel spin relaxation mechanism.…”

Section: Introductionmentioning

confidence: 99%

Spin-polarized multiexcitons in quantum dots in the presence of spin-orbit interaction

et al. 2011

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An efficient electron spin-relaxation mechanism has been observed in InAs quantum dots (QDs) that manifests itself as a sharp drop in the circular polarization of the light emitted by Fe spin-light emitting diodes, which incorporate a single layer of InGaAs QDs, for a narrow range of magnetic fields around 5 tesla. The underlying mechanism occurs when the QDs are occupied by three electron-hole pairs forming a tri-exciton (3X) and is a two step process. The first step involves the spin flip of one of the three electrons mediated by the spin-orbit interaction; in the second step the 3X relaxes to its ground state via phonon emission.

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“…This is often accomplished non-resonantly, i.e. either by electrical injection of spin-polarized carriers 1,[11][12][13][14] or by optical orientation of carrier spins 5 .…”

Section: Introductionmentioning

confidence: 99%

Spin injection in lateral InAs quantum dot structures by optical orientation spectroscopy

et al. 2009

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Abstract. Optical spin injection is studied in novel laterally arranged self-assembled InAs/GaAs quantum dot structures, by using optical orientation measurements in combination with tuneable laser spectroscopy. It is shown that spins of uncorrelated free carriers are better conserved during the spin injection than the spins of correlated electrons and holes in an exciton. This is attributed to efficient spin relaxation promoted by the electron-hole exchange interaction of the excitons. Our finding suggests that separate carrier injection, such as that employed in electrical spin injection devices, can be advantageous for spin conserving injection. It is also found that spin injection efficiency decreases for free carriers with high momentum, due to acceleration of spin relaxation processes.

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Electrical Manipulation of Spin Injection into a Single InAs Quantum Dots

Cited by 3 publications

References 8 publications

Electrical injection of spin‐polarized electrons into single quantum dots

Electrical injection of spin‐polarized electrons into single quantum dots

Spin-polarized multiexcitons in quantum dots in the presence of spin-orbit interaction

Spin injection in lateral InAs quantum dot structures by optical orientation spectroscopy

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