Fast Domain Wall Propagation under an Optimal Field Pulse in Magnetic Nanowires

Abstract

We investigate field-driven domain wall (DW) propagation in magnetic nanowires in the framework of the Landau-Lifshitz-Gilbert equation. We propose a new strategy to speed up the DW motion in a uniaxial magnetic nanowire by using an optimal space-dependent field pulse synchronized with the DW propagation. Depending on the damping parameter, the DW velocity can be increased by about 2 orders of magnitude compared to the standard case of a static uniform field. Moreover, under the optimal field pulse, the change in total magnetic energy in the nanowire is proportional to the DW velocity, implying that rapid energy release is essential for fast DW propagation.

Statics and field-driven dynamics of transverse domain walls in biaxial nanowires under uniform transverse magnetic fields

“…Magnetic DWs can be basic bit units in modern logical [1] and storage [2,3] devices. By applying various driving factors, such as magnetic fields [4][5][6][7][8][9][10][11][12][13][14][15], spin-polarized currents [16][17][18][19][20][21][22][23][24], or temperature gradients [25][26][27][28][29], etc, DWs can be driven to move along wire axis with quite high velocity, which results in high processing speed of devices based on them. Traditionally, the time evolution of the magnetization distribution is described by the nonlinear Landau-Lifshitz-Gilbert (LLG) equation [30].…”

Domain-Wall Motion in Ferromagnetic Nanowires Driven by Arbitrary Time-Dependent Fields: An Exact Result

“…75.78.Fg Introduction.-The motion of magnetic domain walls (DWs) in ferromagnetic nanowires has recently become a subject of intensive research in the condensed matter physics community [1]. Manipulation of DWs by external magnetic fields, and in particular, the question of how the DW propagation velocity depends on the applied field have drawn considerable attention [2][3][4].…”

“…Manipulation of DWs by external magnetic fields, and in particular, the question of how the DW propagation velocity depends on the applied field have drawn considerable attention [2][3][4].…”

FMR Measurements of Magnetic Nanostructures

“…The fabrication of such nanowires in polycarbonate track-etched and anodic alumina membranes have been widely studied during the last 15 years [1-2]. Their potential applications might be explored in spintronic devices and more specifically in magnetic random access memory (MRAM) and magnetic logic devices [3][4][5]. Furthermore, microwave devices, such as circulators or filters for wireless communication and automotive systems can be fabricated on ferromagnetic nanowires embedded in AAO substrates [6][7][8][9].…”