Nanoscale physics

On spintronics properties of antiferromagnetic nanostructures
Korostil A.М.1, Krupa M.M.1  
1Physics of Meso- and Nanocrystalline Magnetic Structures Department, Institute of Magnetism NAS of Ukraine and MES  of Ukraine. Prospect Vernadsky, 36b, Kyiv, Ukraine. E-mail: korostilandrii@gmail.com

An interconnection of spin current with magnetic states represents the base of spintronics properties of magnetic nanostructures independently of the character of the exchange coupling of localized magnetic moments [1]. Interaction between the spin current and localized magnetic states occurs via s-d exchange interaction and a spin torque exerting on the localized magnetic moments in magnetic nanostructures with both ferro- and antiferromagnetic exchange coupling [2]. Electrical control of magnetic dynamics in these magnetic nanostructures occurs through the conversation of the input electric current into the spin current interacting with the localized magnetic moments. The conversation may consist in spin polarization of electrons or spin-orbit-induced pure spin current [2]. Spin dependent electron scattering determines magnetoresistive properties of the magnetic nanostructures with both ferro- and antiferromagnetic exchange interaction. These properties can represent the basis for magnetic recording, storage, readout and processing of information in the GHz and THz frequency ranges in the cases of ferro- and antiferromagnetic exchange interactions. The most promising are antiferromagnetic nanostructutes owing to  robust against magnetic perturbations, produce no stray fields, ultrafast dynamics, and generation large magnetotransport effect. Characteristic properties of the magnetic dynamics and electric control of the magnetic states in the antiferromagnetic nanostructures are described in the framework of the microscopic spin model with the Stoner exchange interaction and spin-orbit interaction. A self-consistence analysis of this model is based on the approach of nonequilibrium real time Green functions. It is shown the role of the staggered spin torque in the electric control of the dynamics of antiferromagnetic order parameter and its switching.   

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2.	Mahfouzi F., Mishra R., Chang P-H,  Yang H., and Kioussis N.  Microscopic origin of spin-orbit torque in ferromagnetic heterostructures: A first-principles approach // Phys. Rev.- 2020.- B 101.-P. 060405.