HALLIWELL SUPERLUMINAL CODE

HALLIWELL SUPERLUMINAL CODE

Homoclinic chaos has been proposed as the most suitable way to code information in time by trains of equal spikes occurring at apparently erratic times a new quantitative indicator, called propensity, is introduced to select the most appropriate neuron model. Thus, the synchronization of spike trains of many individual neurons is the basis of a coherent perception. An external stimulus spreads over an assembly of coupled neurons, building up a corresponding collective state. TitoДЇeature binding denotes how a large collection of coupled neurons combines external signals with internal memories into new coherent patterns of meaning. Feature binding as neuron synchronization: quantum aspects Arecchi, F.Finally, we explore the depth of the analogy between the two classes of problems, and discuss to what extent each case exhibits the characteristic signs of critical behavior at a sharp second-order phase transition. We consider two applications within the first class: thermally induced breakup of monovalent metallic nanowires, and stochastic reversal of magnetization in thin ferromagnetic annuli. It is shown that there exists a mapping from one class of problems to the other, and that their respective transitions can be understood within a unified theoretical context. Each class possesses a transition in its escape behavior, at a critical value of interval length and temperature, respectively. The second class comprises systems in which a single degree of freedom is perturbed by both thermal and quantum noise. The first class, often used to model noise-induced order parameter reversal, comprises Ginzburg-Landau-type field theories defined on finite intervals, perturbed by thermal or other classical spatiotemporal noise. We study two broad classes of physically dissimilar problems, each corresponding to stochastically driven escape from a potential well. Fluctuations, classical activation, quantum tunneling, and phase transitions Stein, D.Thus we show a clear and fundamental example in which transition to chaotic motion in a deterministic classical system, in absence of any external noise, leads to a profound modification in the quantum behavior. However, if we modify the shape of the billiard thus rendering classical (ray) dynamics fully chaotic, the interference fringes disappear and the intensity on the screen becomes the (classical) sum of intensities for the two corresponding one-slit experiments. If the shape of the billiard is such that the classical ray dynamics is regular, we obtain interference fringes whose visibility can be controlled by changing the parameters of the initial state. We then report on the numerical simulation of the double-slit experiment, where the initial wave-packet is bounded inside a billiard domain with perfectly reflecting walls.

In particular we focus our attention on the so called 'fidelity' or Loschmidt echo, its relation with the decay of correlations, and discuss the quantum-classical correspondence. We discuss the stability of quantum motion under system's perturbations in the light of the corresponding classical behavior.

Halliwell superluminal