Microscopic theory of spin waves in magnetic nanowires / Teoria microscÃpica de ondas de spin em nanofios magnÃticos

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The dynamical behavior of spins in magnetic materials is affected by its geometry and dimensionality. One can find several new results in the literature exploiting the magnetic properties of low dimension systems with different geometries, since the development of new devices such as: nanosensors, high density magnetic storage, etc., is closely related to new geometries. In this piece of work, we study the propagation of spin waves on cylindrical magnetic nanowires described by a microscopic theory through the Heisenberg Hamiltonian, where we consider the spins fixed at the sites lattice and the transversal section of the wire is hexagonal. Our model takes into account the exchange interaction between the spins that can be ferromagnetic or antifferomagnetic, the interaction of an external field with the spins (Zeeman interaction), anisotropic interactions due to a preferred direction of magnetization, and finally dipole-dipole interactions. The spins are described by boson operators through Holstein-Primakoff representation. The equations of motion for the spins are written in terms of these operators and translational symmetry in a preferential direction allows us to calculate several excitations spectra.

ASSUNTO(S)

magnetismo ondas de spin ferro/antiferromagnetism dispersion relation materiais magneticos e propriedades magneticas interaÃÃo dipolar interaÃÃo de troca exchange interaction spin waves ferro/antiferromagnetismo relaÃÃo de dispersÃo dipole-dipole interaction magnetism

ACESSO AO ARTIGO

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