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IS Aranson

Publications and source records attributed to IS Aranson.

10 recordsLinked to original sources
PubMed2000

Resonances, instabilities, and structure selection of driven josephson lattice in layered superconductors

We investigate the dynamics of the Josephson vortex lattice in layered high- T(c) superconductors at high magnetic fields. It is shown that the average electric current depends on the lattice structure and is resonantly enhanced when the Josephson frequency matches the frequency of the plasma mode. We find the stability regions of a moving lattice. It is shown that a specific lattice structure at a given velocity is uniquely selected by the boundary conditions; at small velocities a periodic triangular lattice is stable and looses its stability at some critical velocity. At even higher velocities, a structure close to a rectangular lattice is restored.

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PubMed2000

Continuum field description of crack propagation

We develop continuum field model for crack propagation in brittle amorphous solids. The model is represented by equations for elastic displacements combined with the order parameter equation which accounts for the dynamics of defects. This model captures all important phenomenology of crack propagation: crack initiation, propagation, dynamic fracture instability, sound emission, crack branching, and fragmentation.

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PubMed2000

Electrostatically driven granular media: phase transitions and coarsening

We report the experimental and theoretical study of electrostatically driven granular material. We show that the charged granular medium undergoes a hysteretic phase transition from the immobile condensed state (granular solid) to a fluidized dilated state (granular gas) with a changing applied electric field. In addition we observe a spontaneous precipitation of dense clusters from the gas phase and subsequent coarsening-coagulation of these clusters. Molecular dynamics simulations show qualitative agreement with experimental results.

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PubMed2000

Interaction of vortices in a complex vector field and stability of a "Vortex molecule"

We consider interaction of vortices in the vector complex Ginzburg-Landau equation (CVGLE). In the limit of small field coupling, it is found analytically that the interaction between well-separated defects in two different fields is long ranged, in contrast to the interaction between defects in the same field which falls off exponentially. In a certain region of parameters of CVGLE, we find stable rotating bound states of two defects-a "vortex molecule."

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PubMed2000

Patterns in thin vibrated granular layers: interfaces, hexagons, and superoscillons

A theoretical and experimental study of patterns in vibrated granular layers is presented. An order parameter model based on the parametric Ginzburg-Landau equation is used to describe strongly nonlinear excitations including hexagons, interfaces between flat antiphase domains, and new localized objects, superoscillons. The experiments confirm the existence of superoscillons and bound states of superoscillons and interfaces. On the basis of the order parameter model we predict analytically and confirm experimentally that additional subharmonic driving results in the controlled motion of interfaces.

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PubMed2000

Crystallization kinetics and self-induced pinning in cellular patterns

Within the framework of the Swift-Hohenberg model it is shown numerically and analytically that the front propagation between cellular and uniform states is determined by periodic nucleation events triggered by the explosive growth of the localized zero-eigenvalue mode of the corresponding linear problem. We derive an evolution equation for this mode using asymptotic analysis, and evaluate the time interval between nucleation events, and hence the front speed. In the presence of noise, we find the velocity exponent of "thermally activated" front propagation (creep) beyond the pinning threshold.

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