Condensed Matter Seminar Announcement Dr. Helmut G. Katzgraber ETH Zurich " Equilibrium and nonequilibrium properties of spin glasses in a field " Date: Thursday, March 17, 2005 Time: 1:30 pm 416 Physics/Geology Abstract: In order to test the existence of a spin-glass phase in a field at finite temperatures, results of Monte Carlo simulations of the three-dimensional Edwards-Anderson Ising spin glass in the presence of a random field are presented. A finite-size scaling analysis of the correlation length shows no indication of a transition, in contrast to the zero-field case. This suggests that there is no Almeida-Thouless line for short-range Ising spin glasses. The validity of replica symmetry breaking theory versus the droplet picture are discussed, as well as extensions of the above results to long-range models. In addition, hysteretic memory effects in the Edwards-Anderson Ising spin glass, such as reversal-field and return point memory, are investigated with the FORC method.

E-Mail: katzgraber@phys.ethz.ch
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