Self-organization of topological defects for a triangular-lattice magnetic dots array subject to a perpendicular magnetic field

Abstract

The regular array of magnetic particles (magnetic dots) of the form of a two-dimensional triangular lattice in the presence of external magnetic field demonstrates complicated magnetic structures. The magnetic symmetry of the ground state for such a system is lower than that for the underlying lattice. Long range dipole-dipole interaction leads to a specific antiferromagnetic order in small fields, whereas a set of linear topological defects appears with the growth of the magnetic field. Self-organization of such defects determines the magnetization process for a system within a wide range of external magnetic fields.

Metal-Insulator Transition and Band Magnetism in the Spin-$1/2$ Falicov-Kimball Model on A Triangular Lattice with External Magnetic Field

“…Therefore in the present article we would like to explore the ground state properties of the spin-dependent FKM on a triangular lattice with finite external magnetic field which affects the orbital (through Pierels substitution) and spin (through Zeeman coupling or effective Lande g−factor) degrees of freedom of the itinerant d−electrons. These results will be very close to the recent theoretical and experimental findings on the triangular lattice [44,45,46,47]. Many other novel aspects of the correlated electron systems like non-trivial topology in band structure, charge, orbital and magnetic ordered configurations and their metallic or insulating nature are also expected to be uncovered.…”

Theoretical formalism for collective spin-wave edge excitations in arrays of dipolarly interacting magnetic nanodots

“…One of the examples of such self-biased artificial magnetic materials are the arrays of periodically arranged and dipolarly coupled anisotropic magnetic nanoelements, in which the nano-size of the element guarantees its monodomain state, while the shape or/and crystallographic anisotropy determines the definite direction of its static magnetization [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] . The static magnetization of each anisotropic nanoelement can have more than one stable direction, which means that an array can exist in several distinct meta-stable static magnetization states 14,21 . Obviously, the static magnetization state of an array strongly affects the array's dynamic magnetization properties, such as the spectrum of its spin wave excitations and characteristics of the array's interaction with external electromagnetic waves 17,19,23 .…”

“…These "self-biased" magnetic materials, which can function without heavy and bulky external permanent magnets, will be very attractive for applications in microwave signal processing and magnetic logic. One of the examples of such self-biased artificial magnetic materials are the arrays of periodically arranged and dipolarly coupled anisotropic magnetic nanoelements, in which the nano-size of the element guarantees its monodomain state, while the shape or/and crystallographic anisotropy determines the definite direction of its static magnetization [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] . The static magnetization of each anisotropic nanoelement can have more than one stable direction, which means that an array can exist in several distinct meta-stable static magnetization states 14,21 .…”