Coherent and incoherent vortex flow states in crossed channelsC. J. Olson Reichhardt and C. Reichhardt
Theoretical Division, Los Alamos National Laboratory - Los Alamos, NM 87545, USA
received 26 June 2009; accepted in final form 28 October 2009; published November 2009
published online 25 November 2009
We examine vortex flow states in periodic square pinning arrays with one row and one column of pinning sites removed to create an easy-flow crossed-channel geometry. When a drive is simultaneously applied along both major symmetry axes of the pinning array such that vortices move in both channels, a series of coherent-flow states develop in the channel intersection at rational ratios of the drive components in each symmetry direction when the vortices can cross the intersection without local collisions. The coherent-flow states are correlated with a series of anomalies in the velocity force curves, and in some cases can produce negative differential conductivity. The same general behavior could also be realized in other systems including colloids, particle traffic in microfluidic devices, or Wigner crystals in crossed one-dimensional channels.
74.25.Qt - Vortex lattices, flux pinning, flux creep.
© EPLA 2009