Abstract. In our previous work
devoted to the study of spin–injection mechanism of the THz- generation in
magnetic junctions we established the relation between the frequency of generation
and the angle between magnetizations of the contacting ferromagnetic, and also the
spin polarization of the free electrons in these ferromagnetics. It is shown
that the angle between magnetizations can vary from 0 degree to 180 degree. Based
on the results of previous work, we make a qualitative assessment of the
possibility of multi-frequency nature of THz radiation generation in a magnetic
junction of the film-rode type. In a film-rod magnetic junction there are two
possible areas of the film, in which there is radiation at two different
frequencies. These are the area under the end face of the rod’s tip, where unidirectional
magnetizations have different magnitudes and the area on the boundary of the
rod, where multidirectional magnetizations have also different magnitudes. We
make numerical assessment based on the simplified formula of the relation of
radiation frequency to the directions and magnitude of magnetizations of
layers. Numerical estimations are confirmed by experimental results.
Keywords: The injection of the spin
via current, terahertz radiation, magnetic transition, layer magnetization,
quasi-Fermi levels, radiative quantum transitions.
1. Gulyaev Yu.V., Zilberman P.E., and Chigarev S.G. Spin-injection
terahertz wave generators based metal magnetic structures. // Journal of
Communications Technology and Electronics, 2015,Vol.60, No.5, pp.411-435.
2. Chigarev S.G., Krikunov A.I., Zil’berman P.E,
Panas A.I., and Epshtein E M. Current in a System Formed by a Microprobe and a
Thin-Film Layered Structure. ISSN 1064-2269, Journal of Communications Technology
and Electronics, 2009, Vol. 54, No. 6, pp. 708–712. DOI: 10.1134/S1064226909060138
3. Vilkov E.A., Zil’berman
Moiseev S.G., and ChigarevS.G. The
Magnetostatic Field in a Terahertz Rod/Film Structure // Journal of
Communications Technology and Electronics, 2014, Vol. 59, No.11, pp. 1265-1273.
4. Vilkov E.A., Mikhailov G.M.,
Chigarev S.G., Gulyaev Yu.V., Korenivskii V. N., Nikitov S.A, and Slavin A.N.
Frequency Tuning of the Spin-Injection Radiation in the Magnetic Contact
of Communications Technology and Electronics, 2016, Vol. 61, No. 9, pp.
995–1002. DOI: 10.1134/S1064226916090138
5. Gulyaev Yu.V., Zil’berman P.E., Malikov I.A.,
Mikhailov G.M., Panas A.I., Chigarev S..G, Epstein E.M. The spin-injection
terahertz radiation in magnetic transitions. JETP Letters, Vol. 93, No.5,
pp. 259 - 262 (2011).
6. Gulayev Yu. V, Zil’berman P. E., Kasatkin S. I., Mikhailovc G. M., and Chigarev S. G. Terahertz Emission in the
Ferromagnetic–Antiferromagnetic Structure // Journal of Communications
Technology and Electronics, 2013, Vol. 58, No. 7, pp. 716–719. DOI: 10.1134/S1064226913070073
7. Chigarev S.G, Malikov I.V, Mikhailov G.M. Analysis
of the Frequency Characteristics of the Spin-Injection Emitter in the Terahertz
Using a Diffraction Grating // Journal of Communications Technology and Electronics,
2013, Vol.58, No.3, pp. 238-242. DOI: 10.1134/S106422691301004X