Guchhait Samaresh, Orbach Raymond L
Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758, USA.
Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, USA.
Phys Rev Lett. 2017 Apr 14;118(15):157203. doi: 10.1103/PhysRevLett.118.157203. Epub 2017 Apr 13.
We measure the field dependence of spin glass free energy barriers in a thin amorphous Ge:Mn film through the time dependence of the magnetization. After the correlation length ξ(t,T) has reached the film thickness L=155 Å so that the dynamics are activated, we change the initial magnetic field by δH. In agreement with the scaling behavior exhibited in a companion Letter [M. Baity-Jesi et al., Phys. Rev. Lett. 118, 157202 (2017)PRLTAO0031-900710.1103/PhysRevLett.118.157202], we find that the activation energy is increased when δH<0. The change is proportional to (δH)^{2} with the addition of a small (δH)^{4} term. The magnitude of the change of the spin glass free energy barriers is in near quantitative agreement with the prediction of a barrier model.
