Figure 2

We plot the noise spectrum S(ω) at zero temperature for three different values of s = 0.5, s = 1, s = 3 corresponding to sub-Ohmic, Ohmic and super-Ohmic environments with cutoff frequency Λ = ω0/3, coupling strengths γ = 0.05 and t = 0.1.
We compare the non-Markovian noise power spectrum S(ω) with its Markovian counterpart calculated by using the quantum regression theorem (QRT).