Electron-nucleus spin-correlation conservation of spin-dependent recombination in Ga2+ centers
| Autor: | M. M. Afanasiev, Thierry Amand, V. G. Ibarra-Sierra, Alejandro Kunold, J. C. Sandoval-Santana, Andrea Balocchi, Xavier Marie, L. A. Bakaleinikov, Hélène Carrère, E. L. Ivchenko, V. K. Kalevich |
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| Rok vydání: | 2020 |
| Předmět: |
Physics
Zeeman effect Condensed matter physics Spintronics Electron capture 02 engineering and technology Electron 021001 nanoscience & nanotechnology 01 natural sciences Magnetic field Paramagnetism symbols.namesake 0103 physical sciences symbols 010306 general physics 0210 nano-technology Spin (physics) Hyperfine structure |
| Zdroj: | Physical Review B. 101 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.101.075201 |
| Popis: | Spin-dependent recombination in GaAsN offers many interesting possibilities in the design of spintronic devices mostly due to its astounding capability to reach conduction band electron spin polarization close to 100% at room temperature. The mechanism behind the spin selective capture of electrons in ${\mathrm{Ga}}^{2+}$ paramagnetic centers is revisited in this paper to address inconsistencies common to most previously presented models. Primarily, these errors manifest themselves as major disagreements with the experimental observations of two key characteristics of this phenomenon: the effective Overhauser-like magnetic field and the width of the photoluminescence Lorentzian-like curves as a function of the illumination power. These features are not only essential to understand the spin-dependent recombination in GaAsN, but are also key to the design of novel spintronic devices. Here we demonstrate that the particular structure of the electron capture expressions introduces spurious electron-nucleus correlations that artificially alter the balance between the hyperfine and the Zeeman contributions. This imbalance strongly distorts the effective magnetic field and width characteristics. In this work we propose an alternative recombination mechanism that preserves the electron-nucleus correlations and, at the same time, keeps the essential properties of the spin selective capture of electrons. This mechanism yields a significant improvement to the agreement between experimental and theoretical results. In particular, our model gives results in very good accord with the experimental effective Overhauser-like magnetic field and width data, and with the degree of circular polarization under oblique magnetic fields. |
| Databáze: | OpenAIRE |
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