Nonanalytic magnetic field dependence of the magnetisation in spin glasses

The magnetisation of Ising spin glasses is shown to have a singular contribution, msing varies as hx for h to 0, where x=d/(d+2yT), for all T<Tc, where d is the spatial dimensionality and yT is the thermal exponent associated with the zero-temperature fixed point of the renormalisation group flows. For d=3 the authors predict m= chi (T)h-A(T)hx+ . . ., with x approximately=1.15.