Berlin 2005 – wissenschaftliches Programm

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DY: Dynamik und Statistische Physik

DY 34: Poster

DY 34.105: Poster

Montag, 7. März 2005, 15:30–18:00, Poster TU D

Kinetic Ising Model with Memory — •Thomas Michael and Steffen Trimper — Fachbereich Physik, Martin-Luther-Universität, Friedemann-Bach-Platz, 06108 Halle

The kinetic Ising model is studied alternatively by using a second quantized formalism for the underlying Master equation. Whereas in the original model due to Glauber the temperature is incorporated in the transition probability for the single spin-flip-process, in our approach the temperature is taken into account from the beginning by introducing a pseudo-Heisenberg picture of the operators. The method enables us to calculate the moments by applying the algebraic properties of the Pauli-operators. As a result we get an exact expression for the transition probability with a time scale, depending on the relevant spin variable. In the vicinity of the critical point the transition probability is similar to the original expression where the differences will be discussed, especially for low temperatures. Near to the phase transition it is possible to derive a Ginzburg-Landau expansion. As an extension of our procedure we study the influence of short and long range memory effects within the kinetic Ising model. Near to Tc we observe an oscillatory behaviour.