Memory and chaos in an Ising spin glass -: art. no. 012411

The nonequilibrium dynamics of the model three-dimensional Ising spin glass-Fe0.55Mn0.45TiO3-has been investigated from the temperature and time dependence of the zero-field-cooled magnetization recorded under certain thermal protocols. The results manifest chaos, rejuvenation, and memory features of the equilibrating spin configuration that are very similar to those observed in corresponding studies of the archetypal RKKY spin glass Ag(Mn). The sample is rapidly cooled in zero magnetic field and the magnetization recorded on reheating. When a stop at constant temperature T-s is made during the cooling the system evolves toward its equilibrium state at this temperature, The equilibrated state established during the stop becomes frozen in on further cooling and is retrieved on reheating. The memory, of the aging at T-s is not affected by a second stop at a lower temperature T-s'. Reciprocally, the first equilibration at T-s has no influence on the relaxation at T-s'. as expected within the droplet model for domain growth in a chaotic landscape.