Daniel Tennant - University of Texas, Austin
I will report on dynamical magnetic susceptibility measurements of
both bulk and thin film samples of the spin glass Copper Manganese.
By studying the Thermoremanent Magnetization (TRM) of multi-layer thin
films of various thicknesses, we are able to show the maximum energy
barrier encountered during correlated spin flip transitions is cut off
by the thickness of the film and is independent of temperature. The
distribution of energy barriers is shown to follow from a hierarchical
model as opposed to the Droplet Model. Spin glasses, like many
complex systems, exhibit aging; the time spent in the system’s initial
state influences its response to perturbation. By conducting waiting
time experiments with the TRM, it is shown that aging is intimately
tied to the growth of correlated regions in the Copper Manganese
samples.