Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fidelity trade-off for finite ensembles of identically prepared qubits   We calculate the trade-off between the quality of estimating the quantum
state of an ensemble of identically prepared qubits and the minimum level of
disturbance that has to be introduced by this procedure in quantum mechanics.
The trade-off is quantified using two mean fidelities: the operation fidelity
which characterizes the average resemblance of the final qubit state to the
initial one, and the estimation fidelity describing the quality of the obtained
estimate. We analyze properties of quantum operations saturating the
achievability bound for the operation fidelity versus the estimation fidelity,
which allows us to reduce substantially the complexity of the problem of
finding the trade-off curve. The reduced optimization problem has the form of
an eigenvalue problem for a set of tridiagonal matrices, and it can be easily
solved using standard numerical tools.

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The categories of this paper are: math-ph
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The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
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The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: hep-th
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The categories of this paper are: comp-gas
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The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs