Quantum dynamics of a qubit coupled with a structured bath
Peihao Huang, H Zheng · Journal of Physics Condensed Matter · 2008
The dynamics of an unbiased spin-boson model with Lorentzian spectral density is investigated theoretically in terms of the perturbation theory based on a unitary transformation. The population difference P ( t ) and susceptibility χ '' (ω) are calculated for both the off-resonance case and the on-resonance case Δ∼Ω. The approach is checked by Shiba's relation and the sum rule. As well, the coherent–incoherent transition point α c can be determined.