dorsal/arxiv
View SchemaUniversal observable detecting all two-qubit entanglement and determinant based separability tests
| Authors | Remigiusz Augusiak, Maciej Demianowicz, Pawel Horodecki |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0604109 |
| URL | https://arxiv.org/abs/quant-ph/0604109 |
| DOI | 10.1103/PhysRevA.77.030301 |
| Journal | Physical Review A 77, 030301(R) (2008) |
Abstract
We construct a single observable measurement of which mean value on four copies of an {\it unknown} two-qubit state is sufficient for unambiguous decision whether the state is separable or entangled. In other words, there exists a universal collective entanglement witness detecting all two-qubit entanglement. The test is directly linked to a function which characterizes to some extent the entanglement quantitatively. This function is an entanglement monotone under so--called local pure operations and classical communication (pLOCC) which preserve local dimensions. Moreover it provides tight upper and lower bounds for negativity and concurrence. Elementary quantum computing device estimating unknown two-qubit entanglement is designed.
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"abstract": "We construct a single observable measurement of which mean value on four\ncopies of an {\\it unknown} two-qubit state is sufficient for unambiguous\ndecision whether the state is separable or entangled. In other words, there\nexists a universal collective entanglement witness detecting all two-qubit\nentanglement. The test is directly linked to a function which characterizes to\nsome extent the entanglement quantitatively. This function is an entanglement\nmonotone under so--called local pure operations and classical communication\n(pLOCC) which preserve local dimensions. Moreover it provides tight upper and\nlower bounds for negativity and concurrence. Elementary quantum computing\ndevice estimating unknown two-qubit entanglement is designed.",
"arxiv_id": "quant-ph/0604109",
"authors": [
"Remigiusz Augusiak",
"Maciej Demianowicz",
"Pawel Horodecki"
],
"categories": [
"quant-ph"
],
"doi": "10.1103/PhysRevA.77.030301",
"journal_ref": "Physical Review A 77, 030301(R) (2008)",
"title": "Universal observable detecting all two-qubit entanglement and determinant based separability tests",
"url": "https://arxiv.org/abs/quant-ph/0604109"
},
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