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- Fedorych, OM, et al.
(author)
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Electrically detected magnetic resonance
- 2004
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In: Acta Physica Polonica. Series A: General Physics, Physics of Condensed Matter, Optics and Quantum Electronics, Atomic and Molecular Physics, Applied Physics. - 0587-4246. ; 105:6, s. 591-598
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Journal article (peer-reviewed)abstract
- We compare the results of electrically detected magnetic resonance in a 2D electron gas in Si/SiGe quantum wells with transport and magnetic resonance measurements on ferromagnetic Ga1-xMnxAs. The results lead us to the conclusion that observation of electrically detected magnetic resonance is possible only in the case of a slow spin relaxation, where the microwave resonant absorption leads to a noticeable change of spin magnetization.
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2. |
- Fedorych, OM, et al.
(author)
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Magnetic order in semiconducting, ferromagnetic Ga1-xMnxAs
- 2004
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In: Semiconductor Science and Technology. - : IOP Publishing. - 0268-1242 .- 1361-6641. ; 19:4, s. 492-493
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Journal article (peer-reviewed)abstract
- Magnetic resonance studies allow us to distinguish paramagnetic, ferromagnetic and ferrimagnetic phases in Ga1-xMnxAs. The transition from ferromagnet to ferrimagnet is correlated with a metal to insulator transition. The analysis of spin wave resonance spectra, which occur in the ferrimagnetic phase, allows us to estimate the magnitude and the distance dependence of exchange coupling. The experimentally evaluated long range of exchange causes an effective averaging of the fluctuation of exchange interactions. As a consequence, in the semimetallic phase both spin subsystems coherently precess forming the ferrimagnetic structure. In the insulating phase, fluctuations of the local exchange field lead to a fast decoherence of the carrier spins and only the localized Mn spins form the ferromagnetic moment.
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