G. G. Kenning

Full aging in spin glasses.

The discovery of dynamic memory effects in the magnetization decays of spin glasses in 1983 marked a turning point in the study of the highly disordered spin glass state. Detailed studies of the memory effects have led to much progress in understanding the qualitative features of the phase space. Even so, the exact nature of the magnetization decay functions has remained elusive, causing confusion. In this Letter, we report strong evidence that the thermoremanent magnetization decays scale with the waiting time t(w). By employing a series of cooling protocols, we demonstrate that the rate at which the sample is cooled to the measuring temperature plays a major role in the determination of scaling. As the effective cooling time t(eff)(c) decreases, t/t(w) scaling improves and for t(eff)(c)<20 s we find almost perfect t/t(w) scaling, i.e., full aging.

Intermittent quakes and record dynamics in the thermoremanent magnetization of a spin-glass

A method for analyzing the intermittent behavior of linear response data in aging systems is presented and applied to the spin-glass thermoremanent magnetization (TRM) data of Rodriguez et al. [Phys. Rev. Lett. 91, 037203 (2003)]. The probability density function of the magnetic fluctuations has an asymmetric exponential tail, showing that the demagnetization process occurs through intermittent spin rearrangements or quakes which significantly differ from reversible fluctuations having a Gaussian distribution with zero average. The intensity of quakes is determined by the TRM decay rate, which in turn depends on

From linear to nonlinear response in spin glasses: Importance of mean-field-theory predictions

t

Dimensionality crossover in CuMn spin‐glass films

, the time since the initial quench and on

Magnetic susceptibility and magnetic resonance of a composition‐modulated spin glass

{t}_{w}

Thermally activated magnetization and resistance decay during near ambient temperature aging of Co nanoflakes in a confining semi-metallic environment

, the time at which the magnetic field is cut. For a broad range of temperatures, these dependences are extracted numerically from the data and described analytically using the assumption that the systems linear response is fully subordinated to the occurrence of the quakes which spasmodically release the imbalances created by the initial quench.

Effect of magnetic fields on the relaxation of the thermoremanent magnetization in spin glasses

The scaling of the magnetic field dependence of the remanent magnetization for different temperatures and different spin-glass samples is studied. Particular attention is paid to the effect of the de Almeida-Thouless (AT) critical line on spin-glass dynamics. It is shown that results of the mean-field theory of aging phenomena, with two additional experimentally justified assumptions, predict

Development of a nanoparticle time-temperature sensor for passive and active RFID

H/H_{AT}(T)

Temperature dependence of effective fluctuation time scales in spin glasses

scaling for remanent magnetization curves. Experiments on a single crystal Cu:Mn 1.5 at % sample in the temperature interval from

Magnetic‐field dependence of Tg in bulk Cu:Mn and Cu:Mn/Cu multilayer systems

0.7T_{g}