Fluctuation-dissipation relation in a spin glass in the non-stationary regime
Abstract
We present the first experimental determination of the time autocorrelation C( t‧, t) of magnetization in the non-stationary regime of a spin glass. Quantitative comparison with the corresponding response, the magnetic susceptibility χ( t‧, t), is made possible by the use of a new experimental setup allowing both measurements in the same conditions. Clearly, we observe a non-linear fluctuation-dissipation relation between C and χ, depending weakly on the waiting time t‧. Following theoretical developments on mean-field models, and lately on short range ones, it is predicted that in the limit of long times, the χ( C) relationship should become independent on t‧. A scaling procedure allows us to extrapolate to the limit of long waiting times.
- Publication:
-
Physica B Condensed Matter
- Pub Date:
- May 2003
- DOI:
- 10.1016/S0921-4526(02)02228-7
- Bibcode:
- 2003PhyB..329.1028H
- Keywords:
-
- Spin glass;
- Non-stationarity;
- Fluctuation-dissipation relation