Violation of fluctuationdissipation theorem in the offequilibrium dynamics of a system with non additive interactions

PINTO O. A; ROMA F.; RAMÍREZ-PASTOR A.J.; NIETO F. D.

American Institute of Physics.

Año: 2011 vol. 1332 p. 292 - 292

In this work we study the critical equilibrium properties and the off-equilibrium dynamics of an Isingsystem with non additive interactions. The traditional assumption of additivity is modified for one moregeneral, where the energy of exchange J between two spins depends on their neighbourhood. First, forseveral non additive situations, we calculated the critical temperature Tc by using paralell temperingMonte Carlo in the canonical assemble and standard finite-size scaling techniques. Then, we carry out aquench from infinite temperature to a low temperature below Tc (off-equilibrium dynamics protocol) andwe compute two-time correlation and response functions. We find a violation of fluctuation-dissipationtheorem like coarsening systems. All this was done for several waiting time and several non additivesituations. Finally, we analyze the scaling of correlation and response functions for a critical quench frominfinite temp