Activated scaling of classical and quantum spin glasses

作者：Barbara B^*

来源：Physical Review Letters, 2007, 99(17): 177201.

DOI：10.1103/PhysRevLett.99.177201

A model for thermally activated dynamics in disordered systems shows that the linear and nonlinear susceptibility follows a generic exponential form with a "critical rounding,'' X-1 proportional to X-3 proportional to [T ln(t/tau(1)(0))/ K](gamma/b phi) exp - [T tau(phi b ln)(g)(t/tau(1)(0))/ K](v/b) (temperature, t = time, K = barrier constant, t(g) = 1 - T-SG/T, and T-SG = transition temperature; gamma > 0 for X-3 and < 0 for X-1). This model, also valid in the presence of resonant tunneling states at energies K-0 << K [provided that K is replaced by K-0 + 2T ln (1/Gamma(0)), where Gamma(2)(0) proportional to tunnel splitting of a spin S = 1], is potentially applicable to a wide variety of systems opening the way for the study of thermally activated quantum phase transitions. The famous spin-glass system LiHoxY1-x seems to follow this model.

• 出版日期2007-10-26