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arXiv · 1002.0612

Memory and rejuvenation in a spin glass

R. Mathieu·M. Hudl·P. Nordblad
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Abstract

The temperature dependence of the magnetisation of a Cu(Mn) spin glass ($T_g$ $\approx$ 57 K) has been investigated using weak probing magnetic fields ($H$ = 0.5 or 0 Oe) and specific thermal protocols. The behaviour of the zero-field cooled, thermoremanent and isothermal remanent magnetisation on (re-)cooling the system from a temperature (40 K) where the system has been aged is investigated. It is observed that the measured magnetisation is formed by two parts: (i) a temperature- and observation time-dependent thermally activated relaxational part governed by the age- and temperature-dependent response function and the (latest) field change made at a lower temperature, superposed on (ii) a weakly temperature-dependent frozen-in part. Interestingly we observe that the spin configuration that is imprinted during an elongated halt in the cooling, if it is accompanied by a field induced magnetisation, also includes a unidirectional excess magnetisation that is recovered on returning to the ageing temperature.

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R. Mathieu, M. Hudl, P. Nordblad. 2010-05-06. Memory and rejuvenation in a spin glass. https://doi.org/10.1209/0295-5075%2F90%2F67003

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