dorsal/arxiv
View SchemaQuantum reverse-engineering and reference frame alignment without non-local correlations
| Authors | E. Bagan, M. Baig, R. Munoz-Tapia |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0405082 |
| URL | https://arxiv.org/abs/quant-ph/0405082 |
| DOI | 10.1103/PhysRevA.70.030301 |
| Journal | Phys. Rev. A 70, 030301 (2004) |
Abstract
Estimation of unknown qubit elementary gates and alignment of reference frames are formally the same problem. Using quantum states made out of $N$ qubits, we show that the theoretical precision limit for both problems, which behaves as $1/N^{2}$, can be asymptotically attained with a covariant protocol that exploits the quantum correlation of internal degrees of freedom instead of the more fragile entanglement between distant parties. This cuts by half the number of qubits needed to achieve the precision of the dense covariant coding protocol.
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"abstract": "Estimation of unknown qubit elementary gates and alignment of reference\nframes are formally the same problem. Using quantum states made out of $N$\nqubits, we show that the theoretical precision limit for both problems, which\nbehaves as $1/N^{2}$, can be asymptotically attained with a covariant protocol\nthat exploits the quantum correlation of internal degrees of freedom instead of\nthe more fragile entanglement between distant parties. This cuts by half the\nnumber of qubits needed to achieve the precision of the dense covariant coding\nprotocol.",
"arxiv_id": "quant-ph/0405082",
"authors": [
"E. Bagan",
"M. Baig",
"R. Munoz-Tapia"
],
"categories": [
"quant-ph"
],
"doi": "10.1103/PhysRevA.70.030301",
"journal_ref": "Phys. Rev. A 70, 030301 (2004)",
"title": "Quantum reverse-engineering and reference frame alignment without non-local correlations",
"url": "https://arxiv.org/abs/quant-ph/0405082"
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