Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum dynamics of a qubit coupled with structured bath   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 non-equilibrium correlation function $P(t)$ and
susceptibility $\chi^{\prime\prime}(\omega)$ are calculated for both the
off-resonance case $\Delta\lesssim 0.5\Omega$ and the on-resonance case
$\Delta\sim \Omega$. The approach is checked by the Shiba's relation and the
sum rule. Besides, the coherent-incoherent transition point $\alpha_c$ can be
determined, which has not been demonstrated for the structured bath by previous
authors up to our knowledge.

9
The categories of this paper are: nlin
19
The categories of this paper are: eess
18
The categories of this paper are: econ
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
3
The categories of this paper are: physics