Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Consistent perturbative treatment of the subohmic spin-boson model
  yielding arbitrarily small $T_2/T_1$ decoherence time ratios   We present a perturbative treatment of the subohmic spin-boson model which
remedies a crucial flaw in previous treatments. The problem is traced back to
the incorrect application of a Markov type approximation to specific terms in
the temporal evolution of the reduced density matrix. The modified solution is
consistent both with numerical simulations and the exact solution obtained when
the bath-coupling spin-space direction is parallel to the qubit energy-basis
spin. We therefore demonstrate that %in distinction to previous findings the
subohmic spin-boson model is capable of %consistently describing arbitrarily
small %(less than two) ratios of the $T_2$ and $T_1$ decoherence times,
associated to the decay of the off-diagonal and diagonal reduced density-matrix
elements, respectively. An analytical formula for $T_2/T_1$ at the absolute
zero of temperature is provided in the limit of a subohmic bath with vanishing
spectral power law exponent. Small ratios closely mimic the experimental
results for solid state (flux) qubits, which are subject predominantly to
low-frequency electromagnetic noise, and we suggest a reanalysis of the
corresponding experimental data in terms of a $nonanalytic$ decay of
off-diagonal coherence.

37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg