Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Incomplete pure dephasing of N-qubit entangled W states   We consider qubits in a linear arrangement coupled to a bosonic field which
acts as a quantum heat bath and causes decoherence. By taking the spatial
separation of the qubits explicitly into account, the reduced qubit dynamics
acquires an additional non-Markovian element. We investigate the time evolution
of an entangled many-qubit W state, which for vanishing qubit separation
remains robust under pure dephasing. For finite separation, by contrast, the
dynamics is no longer decoherence-free. On the other hand, spatial noise
correlations may prevent a complete dephasing. While a standard Bloch-Redfield
master equation fails to describe this behavior even qualitatively, we propose
instead a widely applicable causal master equation. Here we employ it to
identify and characterize decoherence-poor subspaces. Consequences for quantum
error correction are discussed.

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The categories of this paper are: supr-con
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The categories of this paper are: chao-dyn
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The categories of this paper are: chem-ph
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The categories of this paper are: funct-an
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
3
The categories of this paper are: physics
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The categories of this paper are: alg-geom
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The categories of this paper are: stat
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The categories of this paper are: adap-org
2
The categories of this paper are: math
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The categories of this paper are: q-fin
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The categories of this paper are: plasm-ph
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The categories of this paper are: eess
14
The categories of this paper are: math-ph