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Extraction of the Spin Glass Correlation Length

Y. G. Joh·R. Orbach·G. G. Wood·J. Hammann·E. Vincent
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Abstract

The peak of the spin glass relaxation rate, S(t)=d{-M_{TRM}(t,t_w)}/H/{d ln t}, is directly related to the typical value of the free energy barrier which can be explored over experimental time scales. A change in magnetic field H generates an energy E_z={N_s}{X_fc}{H^2} by which the barrier heights are reduced, where X_{fc} is the field cooled susceptibility per spin, and N_s is the number of correlated spins. The shift of the peak of S(t) gives E_z, generating the correlation length, Ksi(t,T), for Cu:Mn 6at.% and CdCr_{1.7}In_{0.3}S_4. Fits to power law dynamics, Ksi(t,T)\propto {t}^{α(T)} and activated dynamics Ksi(t,T) \propto {ln t}^{1/psi} compare well with simulation fits, but possess too small a prefactor for activated dynamics.

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Y. G. Joh, R. Orbach, G. G. Wood, J. Hammann, E. Vincent. 1998-12-21. Extraction of the Spin Glass Correlation Length. https://doi.org/10.1103/physrevlett.82.438

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