Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Distribution of quantum Fisher information in asymmetric cloning
  machines   An unknown quantum state cannot be copied on demand and broadcast freely due
to the famous no-cloning theorem. Approximate cloning schemes have been
proposed to achieve the optimal cloning characterized by the maximal fidelity
between the original and its copies. Here, from the perspective of quantum
Fisher information (QFI), we investigate the distribution of QFI in asymmetric
cloning machines which produce two nonidentical copies. As one might expect,
improving the QFI of one copy results in decreasing the QFI of the other copy,
roughly the same as that of fidelity. It is perhaps also unsurprising that
asymmetric phase-covariant cloning machine outperforms universal cloning
machine in distributing QFI since a priori information of the input state has
been utilized. However, interesting results appear when we compare the
distributabilities of fidelity (which quantifies the full information of
quantum states), and QFI (which only captures the information of relevant
parameters) in asymmetric cloning machines. In contrast to the results of
fidelity, where the distributability of symmetric cloning is always optimal for
any d-dimensional cloning, we find that asymmetric cloning performs always
better than symmetric cloning on the distribution of QFI for $d\leq18$, but
this conclusion becomes invalid when $d>18$.

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The categories of this paper are: stat
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The categories of this paper are: eess
17
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: supr-con
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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: mtrl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: nlin
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-ex
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The categories of this paper are: cmp-lg
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The categories of this paper are: gr-qc
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The categories of this paper are: dg-ga
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The categories of this paper are: chao-dyn