scholarly journals Classification of dynamical switching regimes in a three-layered ferromagnetic nanopillar governed by spin-polarized injection current and external magnetic field. II. Perpendicular anisotropy

2016 ◽  
Vol 8 (5) ◽  
pp. 755-764
Author(s):  
Natalia Vladimirovna Ostrovskaya ◽  
Vladimir Alexandrovich Skidanov ◽  
Maxim Sergeevich Skvortsov
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Injection Current ◽  
Perpendicular Anisotropy ◽  
Switching Regimes ◽  
Spin Polarized

Neutron–antineutron oscillation and discrete symmetries

2018 ◽  
Vol 33 (31) ◽  
pp. 1844016 ◽  
Author(s):  
Zurab Berezhiani ◽  
Arkady Vainshtein
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Text Classification ◽  
Discrete Symmetries ◽  
Rotational Invariance ◽  
Baryon Charge ◽  
Free Particles ◽  
Definition Of ◽  
Charge Formula

We analyze status of [Formula: see text], [Formula: see text] and [Formula: see text] discrete symmetries in application to neutron–antineutron transitions breaking conservation of baryon charge [Formula: see text] by two units. At the level of free particles, all these symmetries are preserved. This includes [Formula: see text] reflection in spite of the opposite internal parities usually ascribed to neutron and antineutron. Explanation, which goes back to the 1937 papers by Majorana and Racah, is based on a definition of parity satisfying [Formula: see text], instead of [Formula: see text], and ascribing [Formula: see text] to both, neutron and antineutron. We apply this to [Formula: see text], [Formula: see text] and [Formula: see text] classification of six-quark operators with [Formula: see text]. It allows to specify operators contributing to neutron–antineutron oscillations. Remaining operators contribute to other [Formula: see text] processes and, in particular, to nuclei instability. We also show that presence of external magnetic field does not induce any new operator mixing the neutron and antineutron provided that rotational invariance is not broken.

scholarly journals Исследование связанной динамики магнитных вихрей в трехслойном проводящем наноцилиндре

2018 ◽  
Vol 60 (6) ◽  
pp. 1045
Author(s):  
С.В. Степанов ◽  
А.Е. Екомасов ◽  
К.А. Звездин ◽  
Е.Г. Екомасов
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Vortex Motion ◽  
Numerical Data ◽  
Sample Plane ◽  
Current Dependence ◽  
Magnetic Vortices ◽  
Lifshitz Equation ◽  
Spin Polarized ◽  
Stationary Vortex

AbstractSolving numerically the generalized Landau–Lifshitz equation, we have carried out the micromagnetic investigation of the dynamics of two dipole-coupled magnetic vortices in a trilayer nanocolumn under the action of the external magnetic field directed perpendicular to the sample plane and spin-polarized electric field. The possible existence of different regimes of vortex motion, depending on the polarized current, is demonstrated. The current dependence of the oscillation frequency for the case of stationary dynamics of coupled vortices with the same frequency has been established. The possibility of controlling the frequency of the stationary vortex motion and tuning the control current amplitude by the external magnetic field is shown. Using the analytical method for simplified description of the dynamics of coupled vortices, the current and magnetic-field dependences of the frequency have been obtained, which are qualitatively consistent with the numerical data.

scholarly journals Generation of fully spin-polarized currents in three-terminal graphene-based transistors

RSC Advances ◽  
2015 ◽  
Vol 5 (106) ◽  
pp. 87411-87415 ◽  
Author(s):  
Rouhollah Farghadan ◽  
Alireza Saffarzadeh
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Graphene Nanoribbons ◽  
Graphene Flake ◽  
Ferromagnetic Electrodes ◽  
Spin Polarized ◽  
Spin Devices

We propose three-terminal spin devices with graphene nanoribbons (terminals) and a graphene flake (channel) to generate a highly spin-polarized current without an external magnetic field or ferromagnetic electrodes.

Appearance of Intrinsic Magnetization in FeMn Antiferromagnetic Film under the Action of Spin-Polarized Current

2020 ◽  
Vol 22 (8) ◽  
pp. 438-446
Author(s):  
A.I. Panas ◽  
◽  
S.G. Chigarev ◽  
E.A. Vilkov ◽  
O.A. Byshevski-Konopko ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Spin Injection ◽  
Point Of View ◽  
Thz Radiation ◽  
Signal Power ◽  
Spin Orbit ◽  
Practical Point ◽  
Conduction Electrons ◽  
Spin Polarized

The article presents the results of research of two spin-injection sources of THz radiation using different structures of thin-film magnetic transitions (MT) with antiferromagnetic (AFM) FeMn film of nanoscale thickness and ferromagnetic (FM) Fe layer. In both variants, the possibility of intrinsic magnetization forming in the AFM film under the action of a spin-polarized current of a relatively small value formed in the FM layer is shown. The physical foundations of this effect based on the AFM sublattices beveling by a spin-polarized current due to the sd-exchange interaction of the conduction electrons spins with the spins of d electrons of the FM crystal lattice are considered. This does not require an external magnetic field. sd-exchange mechanism of excitation of intrinsic magnetization in AFM is an alternative to the spin-orbit mechanism, which has been widely considered recently. The relations for calculating the frequency and power of spin-injection radiation are given. New experimental results have been obtained that develop the concept of the AFM's intrinsic magnetization. The non-thermal nature of spin-injection radiation and the possibility of increasing the efficiency of the emitter operation due to the ordering of the MT structure by an external magnetic field are shown. The way of increasing the efficiency of spin-injection emitters by creating structures with multiple independently operating micro-emitters at frequencies close to 16 THz and with a signal power of up to a hundred microwatts has been determined. In general, it is shown that the use of the effect of excitation of intrinsic magnetization in AFM is of interest, both from the point of view of the development of theoretical ideas about the magnetic properties of AFM, and from a practical point of view for the creation of spin-injection lasers (tasers).

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