Research on spinalorithronics at the Department of Low Temperature Physics of Kharkov National University in 2017-2019

Abstract

In this paper is presented a short review of results about spincaloritronics obtained on the low temperature physics chair of the Kharkiv National University from 2017 till 2019 years. In introduction several new directions in magnetoelectronics are discussed- spintronics, spincaloritronics and magnonics- which emerged with the aim to reduce the energy dissipation in devices of usual semiconductor microelectronics. Spintronic devices hold the promise of faster switching speeds, less total energy consumption, and higher density of circuit elements, lowering the heat production per switching element. This could be achieved by employing the spin of the electrons instead of (or in addition to) the charge. The spin corresponds to the additional quantum mechanical property of an electron that can be described as an intrinsic angular momentum. Realization of the existence of the tunneling magnetoresistance effect observed at room temperature is paving the way for the evolution of solid state memory devices, new type of the memory, and fast programmable logic circuits. In spincaloritronics, which is included as an additional complementary branch to the established field of spintronics and thermoelectricity, the transport of charge, magnetization (spin), or heat, occurs when the corresponding particles (electrons, magnons, or phonons) are driven out of thermodynamic equilibrium. Magnonics is the part of spintronics, or in a more general sense is electronics, studying physical properties of magnetic micro- and nanostructures, properties of propagating spin waves and also the possibilities of their application for construction of the elemental base of devices at nanolevel for processing, transmission and memory of the information on the basis of new physical principles. In next section the main results of the four papers, published in Physical Revew B are discussed: 1) nonlinear relaxation between magnons and phonons in insulating ferromagnets 2) role of magnons and the size effect in heat transport through an insulating ferromagnet-insulator interface 3) spin Seebeck effect and phonon energy transfer in heterostructures containing layers of normal metal and ferroinsulator 4) temperature dependence of the magnon-phonon energy relaxation time in a ferromagnet insulator.