Memory interference effects in spin glasses
Department of Materials Science, Uppsala University, Box 534, SE-751 21 Uppsala,
2 Service de Physique de l'État Condensé, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
Published online: 15 January 2000
When a spin glass is cooled down, a memory of the cooling process is imprinted in the spin structure. This memory can be disclosed in a continuous heating measurement of the ac-susceptibility. E.g., if a continuous cooling process is intermittently halted during a certain aging time at one or two intermediate temperatures, the trace of the previous stop(s) is recovered when the sample is continuously re-heated . However, heating the sample above the aging temperature, but keeping it below Tg, erases the memory of the thermal history at lower temperatures. We also show that a memory imprinted at a higher temperature can be erased by waiting a long enough time at a lower temperature. Predictions from two complementary spin glass descriptions, a hierarchical phase space model and a real space droplet picture are contested with these memory phenomena and interference effects.
PACS: 75.50.Lk – Spin glasses and other random magnets / 75.10.Nr – Spin-glass and other random models / 75.40.Gb – Dynamic properties (dynamic susceptibility, spin waves, spin diffusion, dynamic scaling, etc.)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000