Nonequilibrium dynamics in a three-dimensional spin glass

Nonequilibrium dynamics in a AE(11% Mn) spin glass has been studied by low frequency ac-susceptibility and magnetic relaxation experiments. The result s unequivocally show that spin structures that memorize the cooling process are imprinted in the system. These imprinted structures disclose themselve s through dramatic changes of the dynamics on reheating the spin glass thro ugh the temperatures where intermittent halts or changes of the cooling rat e have been imposed. We can qualitatively interpret our results in terms of a real space picture based upon spin-glass domains, droplet excitations an d chaos. [S0163-1829(99)03813-8].