Europhys. Lett., 61 (4) , pp. 473-479 (2003)
Structural similarity between the magnetic-flux profile in superconductors and the surface of a 2d rice pileM. S. Welling, C. M. Aegerter and R. J. Wijngaarden
Division of Physics and Astronomy, Vrije Universiteit De Boelelaan 1081, 1081HV Amsterdam, The Netherlands
(Received 31 May 2002; accepted in final form 4 December 2002)
We analyze the magnetic-flux profile in the critical state of an 7-x thin film. It is found that the profile forms a self-affine structure in both space and time. Furthermore, the surface of a pile of rice is studied, which also shows a self-affine structure. These experimental results are compared to simulations of a two-dimensional version of the Oslo model for sandpiles. The exponents characterizing the roughness and dynamics of the profiles for both experimental systems agree with each other, the values being for the roughness exponents and for the growth exponents. These values are reproduced in the simulations as well. This shows that a simple sandpile model can be used to describe the shape and dynamics of the vortex landscape in the critical state. Conversely, superconductors may be used as a model granular system.
05.65.+b - Self-organized systems.
45.70.Vn - Granular models of complex systems; traffic flow.
74.60.Ge - Flux pinning, flux creep, and flux-line lattice dynamics.
© EDP Sciences 2003