Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dephasing of entangled qubits   We investigate the influence of nearby two-level systems on the dynamics of a
qubit. The intrinsic decoherence is given by a coupling of both the qubit and
the two-level systems to a heat bath. Assuming weak interactions between the
qubit and the two-level systems we show that the dephasing of the qubit follows
a multi-exponential decay. For a flat distribution of energy splittings of the
two-level systems the multi-exponential behavior simplifies to a good
approximation to a single exponential decay. The rate is given by the sum of
the dephasing rate of the isolated qubit plus all relaxation rates for the
two-level systems out of their present state. This latter contribution sums up
to a rate approximately given by the mean coupling between the qubit and the
two-level systems times the number of thermally active neighbors.

33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
2
The categories of this paper are: math
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci