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arXiv · 0803.0028

Indirect exchange coupling between localized magnetic moments in carbon nanotubes: a dynamic approach

A. T. Costa·R. B. Muniz·M. S. Ferreira
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Abstract

Magnetic moments dilutely dispersed in a metallic host tend to be coupled through the conduction electrons of the metal. This indirect exchange coupling, known to occur for a variety of magnetic materials embedded in several different metallic structures, is of rather long range, especially for low-dimensional structures like carbon nanotubes. Motivated by recent claims that the indirect coupling between magnetic moments in precessional motion has a much longer range than its static counterpart, here we consider how magnetic atoms adsorbed to the walls of a metallic nanotube respond to a time-dependent perturbation that induces their magnetic moments to precess. By calculating the frequency-dependent spin susceptibility we are able to identify resonant peaks whose respective widths provide information about the dynamic aspect of the indirect exchange coupling. We show that by departing from a purely static representation to another in which the moments are allowed to precess, we change from what is already considered a long range interaction to another whose range is far superior. In other words, localized magnetic moments embedded in a metallic structure can feel each other's presence more easily when they are set in precessional motion. We argue that such an effect can have useful applications leading to large-scale spintronics devices.

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A. T. Costa, R. B. Muniz, M. S. Ferreira. 2008-02-29. Indirect exchange coupling between localized magnetic moments in carbon nanotubes: a dynamic approach. https://arxiv.org/abs/0803.0028

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