Dynamics of a Paramagnetic Colloidal Particle driven on a Magnetic Bubble Lattice

SOBA; TIERNO; FISHER; SAGUES

PHYSICAL REVIEW E - STATISTICAL PHYSICS, PLASMAS, FLUIDS AND RELATED INTERDISCIPLINARY TOPICS

Año: 2008 vol. 77 p. 1 - 4

1063-651X

We present a theoretical study of the recently observed dynamical regimes of paramagnetic col- loidal particles externally driven above a regular lattice of magnetic bubbles. [P. Tierno, T. H. Johansen and T. M. Fischer, Phys. Rev. Lett. 98, 028301 (2007)]. An external precessing mag- netic ¯eld alters the potential generated by the surface of the ¯lm in such a way to either drive the particle circularly around one bubble, ballistically through the array, or in triangular orbits on the interstitial regions between the bubbles. In the ballistic regime, we observe di®erent trajectories performed by the particles phase-locked with the external driving. Superdi®usive motion, which was experimentally found bridging the localized and delocalized dynamics, emerge only by introducing a certain degree of randomness into the bubbles size distribution.