Extracting free-energy landscape of AgMn spin glass thin films with 1/f resistance fluctuations

The temperature dependent 1/f noise in AgMn (12 at.%) thin films with multiple thicknesses (15, 20, 40, 60, 80, 100nm) is reported. The noise measurement provides the unique ability to probe the fundamental dynamics of a spin glass in zero field below the glass temperature. There is a significant increase in the magnitude of the noise in the spin glass state. Analysis of the temperature dependent exponent provides information on the energy barrier distribution and height which are related to the spin glass correlation length. We compare our results with those made previously on CuMn (13.5 at.%) thin films of similar thicknesses¹ and observe a similar trend of the increase of the barrier height with respect to thickness, but with relatively lower values for AgMn as compared to CuMn.

1. D. C. Harrison et al.a, Phys. Rev. B 105, 014413 (2022).