Nonlinear magnetic excitation in terms of solitary waves and solitons in ferromagnetic systems is well studied problem in the literature. The results reveal that the dynamics is governed by Landau - Lifshitz (LL) equation which can be mapped to Nonlinear Schrodinger (NLS) family of equations [1]. Studies with spin transfer torque in both multilayer system and single layer system has attracted much interest in the past several years [2, 3]. The result shows that spin current plays a crucial role on the dynamics of ferromagnetic system. In recent years, the study on nonlinear systems with spatial periodicity has become a great topic of interest. BEC in optical lattices, solitons in Photonic lattices and periodic magnetic systems etc., are the typical models among them [4]. Motivated by the above considerations, we investigate the nonlinear localized magnetic excitations in one dimensional magnonic crystal under periodic magnetic field with spin current. Magnonic crystal is a medium with spatially periodic variation of their magnetic properties in a definite direction. The governing modified Landau - Lifshitz (LL) equation of magnonic crystal with spin current is [5], ∂M(r, t)/ ∂t = -γ(M(r, t) x H) + τ (1) where γ is the gyromagnetic ratio, M(r, t) is the magnetization of the magnonic crystal medium and H is the effective field. The effective field is in general sum of several components includes the exchange field, Anisotropy field, demagnetization field and applied field which can all be space dependent.
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