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تسجيل مستخدم جديدPolarizability of electrically induced magnetic vortex plasma
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Electric field control of magnetic structures, particularly topological defects in magnetoelectric materials, draws a great attention in recent years, which has led to experimental success in creation and manipulation by electric field of single magnetic defects, such as domain walls and skyrmions. In this work we explore a scenario of electric field creation of another type of topological defects -- magnetic vortices and antivortices, which are characteristic for materials with easy plane (XY) symmetry. Each magnetic (anti)vortex in magnetoelectric materials (such as type-II multiferroics) possesses a quantized magnetic and an electric charge, where the former is responsible for interaction between vortices and the latter couples the vortices to electric field. This property of magnetic vortices opens a peculiar possibility of creation of magnetic vortex plasma by non-uniform electric fields. We show that the electric field, created by a cantilever tip, produces a magnetic atom with a localized spatially ordered spot of vortices (nucleus of the atom) surrounded by antivortices (electronic shells). We analytically find the vortex density distribution profile and temperature dependence of polarizability of this structure and confirm it numerically. We show that electric polarizability of the magnetic atom depends on temperature as $alpha sim 1/T^{1-eta}$ ($eta>0$), which is consistent with Euclidean random matrix theory prediction.
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