Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum Cost Efficient Scheme for Violating the Holevo Bound and Cloning
  in the Presence of Deutschian Closed Timelike Curves   Brun \emph{et al.} [Phys. Rev. Lett. \textbf{102}, 210402 (2009)] showed that
in the presence of a Deutschian closed timelike curve (D-CTC), one could
violate the Holevo bound. It is possible to utilize the Holevo bound violation
to encode $n$-bit classical information in a single qubit. Here we demonstrate
a new quantum cost efficient scheme, for storing and retrieving $n$-bit
classical information faithfully in the presence of a D-CTC in violation of the
Holevo bound. We also propose a new protocol for cloning a qubit in the
presence of a D-CTC. In both the schemes, the quantum cost is found to be of
order $O(n)$, which provides an advantage over the existing schemes having
quantum cost of exponential order.

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The categories of this paper are: astro-ph
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The categories of this paper are: hep-th
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The categories of this paper are: gr-qc
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The categories of this paper are: q-fin
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The categories of this paper are: chao-dyn
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The categories of this paper are: supr-con
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The categories of this paper are: hep-ex
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The categories of this paper are: solv-int
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The categories of this paper are: q-alg
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The categories of this paper are: math-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: atom-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: nlin
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The categories of this paper are: physics
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The categories of this paper are: cmp-lg