dorsal/arxiv
View SchemaMaximum observable correlation for a bipartite quantum system
| Authors | Michael J. W. Hall, Erika Andersson, Thomas Brougham |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0609076 |
| URL | https://arxiv.org/abs/quant-ph/0609076 |
| DOI | 10.1103/PhysRevA.74.062308 |
| Journal | Phys. Rev. A 74 (2006) 062308 |
Abstract
The maximum observable correlation between the two components of a bipartite quantum system is a property of the joint density operator, and is achieved by making particular measurements on the respective components. For pure states it corresponds to making measurements diagonal in a corresponding Schmidt basis. More generally, it is shown that the maximum correlation may be characterised in terms of a `correlation basis' for the joint density operator, which defines the corresponding (nondegenerate) optimal measurements. The maximum coincidence rate for spin measurements on two-qubit systems is determined to be (1+s)/2, where s is the spectral norm of the spin correlation matrix, and upper bounds are obtained for n-valued measurements on general bipartite systems. It is shown that the maximum coincidence rate is never greater than the computable cross norm measure of entanglement, and a much tighter upper bound is conjectured. Connections with optimal state discrimination and entanglement bounds are briefly discussed.
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"abstract": "The maximum observable correlation between the two components of a bipartite\nquantum system is a property of the joint density operator, and is achieved by\nmaking particular measurements on the respective components. For pure states it\ncorresponds to making measurements diagonal in a corresponding Schmidt basis.\nMore generally, it is shown that the maximum correlation may be characterised\nin terms of a `correlation basis\u0027 for the joint density operator, which defines\nthe corresponding (nondegenerate) optimal measurements. The maximum coincidence\nrate for spin measurements on two-qubit systems is determined to be (1+s)/2,\nwhere s is the spectral norm of the spin correlation matrix, and upper bounds\nare obtained for n-valued measurements on general bipartite systems. It is\nshown that the maximum coincidence rate is never greater than the computable\ncross norm measure of entanglement, and a much tighter upper bound is\nconjectured. Connections with optimal state discrimination and entanglement\nbounds are briefly discussed.",
"arxiv_id": "quant-ph/0609076",
"authors": [
"Michael J. W. Hall",
"Erika Andersson",
"Thomas Brougham"
],
"categories": [
"quant-ph"
],
"doi": "10.1103/PhysRevA.74.062308",
"journal_ref": "Phys. Rev. A 74 (2006) 062308",
"title": "Maximum observable correlation for a bipartite quantum system",
"url": "https://arxiv.org/abs/quant-ph/0609076"
},
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