| 1. |
- Vilkov, E. A., et al.
(author)
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Dynamics of Spatially Inhomogeneous Spin Polarization of Nonequilibrium Conduction Electrons in Magnetic Transitions
- 2019
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In: Physics of the solid state. - : PLEIADES PUBLISHING INC. - 1063-7834 .- 1090-6460. ; 61:6, s. 941-951
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Journal article (peer-reviewed)abstract
- The equation of the dynamics of the magnetic moment motion that has been averaged over the ensemble of nonequilibrium spin-injected electrons in a ferromagnetic transition in the presence of exchange interaction, interaction with an external electromagnetic field, and a thermostat has been obtained taking into account the spatial inhomogeneity of the charge carrier distribution. It has been shown that taking into account the spatial inhomogeneity of the charge carrier distribution in the equation of the dynamics of the magnetic moment motion allows for describing the various processes of electron transfer in the magnetic transition. The probability of quantum transitions of electrons with opposite spin directions, which determine spin relaxation in interaction with a thermostat, has been estimated. It has been shown that the anisotropy of the radiation medium is determined not only by the anisotropy of the sd-exchange tensor, but also by the additional anisotropy that is caused by the electron impulse derivatives of this tensor. The considered phenomena have a great potential for the detection of new effects and development of new devices based on them, including compact tunable radiation sources in the terahertz frequency range, which is obviously difficult to generate.
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| 2. |
- Vilkov, E. A., et al.
(author)
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Spin Polarization Dynamics of Nonequilibrium Conduction Electrons in Magnetic Junctions
- 2018
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In: Journal of Experimental and Theoretical Physics. - : Pleiades Publishing. - 1063-7761 .- 1090-6509. ; 127:6, s. 1022-1032
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Journal article (peer-reviewed)abstract
- The dynamics of the motion of the magnetic moment averaged over an ensemble of nonequilibrium spin-injected electrons in a ferromagnetic junction is considered with allowance for the exchange interaction, as well as the interaction with an external electromagnetic field and a thermostat. The solution of this problem is important for the experimental development of compact terahertz-band radiation sources. The rate of quantum transitions of electrons with opposite spins, which determine the spin relaxation under the interaction with a thermostat, is calculated within the density matrix formalism. It is shown that two spin-relaxation modes can be implemented that correspond to low- and high-Q precession of spin-nonequilibrium injected electrons. The effect of the characteristic features of spin-flip transitions under the relaxation of the magnetic moment on the emission and absorption of photons with-energy corresponding to the energy of effective exchange splitting of spin subbands is discussed.
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| 3. |
- Vilkov, E. A., et al.
(author)
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Динамика пространственно неоднородной спиновой поляризации неравновесных электронов проводимости в магнитных переходах
- 2019
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In: Fizika tverdogo tela. - Moscow. - 0367-3294. ; 61:6, s. 1021-1030
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Journal article (peer-reviewed)abstract
- С учетом пространственной неоднородности распределения носителей заряда получено уравнение динамики движения магнитного момента, усредненного по ансамблю неравновесных спин-инжектированных электронов в ферромагнитном переходе, при наличии обменного взаимодействия, взаимодействия с внешним электромагнитным полем и с термостатом. Показано, что учет пространственной неоднородности распределения носителей заряда в уравнении динамики движения магнитного момента позволяет описать различные процессы переноса электронов в магнитном переходе. Оценена вероятность квантовых переходов электронов с противоположными направлениями спина, определяющих спиновую релаксацию при взаимодействии с термостатом. Показано, что анизотропия среды излучения определяется не только анизотропией тензора sd-обмена, но также и дополнительной анизотропией, связанной с производными этого тензора по импульсу электронов. Рассмотренные явления имеют большой потенциал для обнаружения новых эффектов и разработки на их основе новых устройств, в том числе компактных перестраиваемых источников излучения в заведомо трудном для генерации терагерцовом диапазоне частот.
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| 4. |
- Vilkov, E. A., et al.
(author)
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Frequency tuning of the spin-injection radiation in the magnetic contact junction
- 2016
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In: Journal of communications technology & electronics. - : Maik Nauka/Interperiodica. - 1064-2269 .- 1555-6557. ; 61:9, s. 995-1002
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Journal article (peer-reviewed)abstract
- The frequency tuning of the terahertz radiation of spin-injection oscillator based on magnetic contact junction that is formed by contacting ferromagnetic metal layers with different magnetizations is analyzed. Under the current-induced spin injection from one magnetic layer (injector) to another (working) layer, the interval of radiation frequencies is determined by the current density in the magnetic contact, the mismatch angle of the magnetizations of injector and working layer, and the equilibrium spin polarization. The wide-range tuning of terahertz frequencies of the spin-injection radiation can be implemented using variations in the above parameters.
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