A particle hops between energy traps with exponential depth distribution ρ(E)~eE/Tg. Below Tg the escape time has infinite mean — the system ages: correlation functions depend on waiting time tw.
Correlation C(t,t_w) vs log(t/t_w)
Trap energy landscape (current position = red)
Parameters
Ready
Bouchaud 1992 μ = T/T_g exponent μ < 1: aging regime C ~ (t_w/t)^μ for large t