Dynamics of radial-magnetized microhelix coils

作者：Fomin Vladimir M^*; Smith Elliot J; Makarov Denys; Sanchez Samuel; Schmidt Oliver G

来源：Physical Review B, 2011, 84(17): 174303.

DOI：10.1103/PhysRevB.84.174303

Radial-magnetized microhelix coils parametrically excited by a magnetic field reveal two distinct types of motion: a rotation at lower excitation frequencies omega(mag) <= 250 degrees s(-1) and an oscillatory-like rotative motion at higher frequencies omega(mag) >= 300 degrees s(-1), which have been detected experimentally [E. J. Smith, D. Makarov, S. Sanchez, V. M. Fomin, and O. G. Schmidt, Phys. Rev. Lett. 107, 097204 (2011)]. We provide a theoretical interpretation of this behavior within a model of nonlinear dynamics with parametric excitation by virtue of an interplay between the magnetic and the damping torques acting on the coil. A close fit to the experimental data is achieved if the shape factor of the coil increases from 0.173 for lower frequencies up to 0.276 at higher frequencies. We also predict a transition from the rotation to the oscillatory-like rotative motion that occurs via a regime, where periods of the rotative motion are interrupted by one or more hiccups (back-and-forth motions) of the coil.

• 出版日期2011-11-21