Braided Rivers and Superconducting Vortex Avalanches
نویسندگان
چکیده
Magnetic vortices intermittently flow through preferred channels when they are forced in or out of a superconductor. We study this behavior using a cellular model, and find that the vortex flow can make braided rivers strikingly similar to aerial photographs of braided fluvial rivers, such as the Brahmaputra. By developing an analysis technique suitable for characterizing a selfaffine (multi)fractal, the scaling properties of the braided vortex rivers in the model are compared with those of braided fluvial rivers. We suggest that avalanche dynamics leads to braiding in both cases. PACS numbers: 64.60Ht, 74.60Ge, 61.43Hb, 92.40Fb
منابع مشابه
Vortex Pinning and Stability in the Low Field, Superconducting Phases of UPt3
We use an array of miniature Hall probe magnetometers to probe the entry and flow of flux in a single crystal torus of the heavy fermion superconductor UPt3. Local measurements over the hole are exquisitely sensitive to vortex motion anywhere in the torus, and they permit us to detect avalanches restricted to and with a sharp onset in the lower temperature superconducting phase. Computer simula...
متن کاملSuperconducting vortex avalanches, voltage bursts, and vortex plastic flow: Effect of the microscopic pinning landscape on the macroscopic properties
Using large-scale simulations on parallel processors, we analyze in detail the dynamical behavior of superconducting vortices undergoing avalanches. In particular, we quantify the effect of the pinning landscape on the macroscopic properties of vortex avalanches and vortex plastic flow. These dynamical instabilities are triggered when the external magnetic field is increased slightly, and are t...
متن کاملDirect observation of stress accumulation and relaxation in small bundles of superconducting vortices in tungsten thin films.
We study the behavior of bundles of superconducting vortices when increasing the magnetic field using scanning tunneling microscopy and spectroscopy at 100 mK. Pinning centers are given by features on the surface corrugation. We find strong net vortex motion in a bundle towards a well-defined direction. We observe continuous changes of the vortex arrangements, and identify small displacements, ...
متن کاملThe formation and propagation of flux avalanches in tailored MgB2 films
The applications of superconducting magnesium diboride are substantially limited by the presence of magnetic flux avalanches at low temperatures. Here, quickly moving magnetic vortices create large amounts of heat and magnetic noise. Such avalanches can be suppressed by evaporating metal layers to the surface of the superconductor, which acts both as a heat sink and as an electromagnetic drag b...
متن کاملImprinting superconducting vortex footsteps in a magnetic layer
Local polarization of a magnetic layer, a well-known method for storing information, has found its place in numerous applications such as the popular magnetic drawing board toy or the widespread credit cards and computer hard drives. Here we experimentally show that a similar principle can be applied for imprinting the trajectory of quantum units of flux (vortices), travelling in a superconduct...
متن کامل