Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum decoherence of a charge qubit in a spin-fermion model   We consider quantum decoherence in solid-state systems by studying the
transverse dynamics of a single qubit interacting with a fermionic bath and
driven by external pulses. Our interest is in investigating the extent to which
the lost coherence can be restored by the application of external pulses to the
qubit. We show that the qubit evolution under various pulse sequences can be
mapped onto Keldysh path integrals. This approach allows a simple diagrammatic
treatment of different bath excitation processes contributing to qubit
decoherence. We apply this theory to the evolution of the qubit coupled to the
Andreev fluctuator bath in the context of widely studied superconducting
qubits. We show that charge fluctuations within the Andreev-fluctuator model
lead to a 1/f noise spectrum with a characteristic temperature depedence. We
discuss the strategy for suppression of decoherence by the application of
higher-order (beyond spin echo) pulse sequences.

3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat