dorsal/arxiv
View SchemaWeak measurements are universal
| Authors | Ognyan Oreshkov, Todd A. Brun |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0503017 |
| URL | https://arxiv.org/abs/quant-ph/0503017 |
| DOI | 10.1103/PhysRevLett.95.110409 |
| Journal | Phys. Rev. Lett. 95, 110409 (2005) |
Abstract
It is well known that any projective measurement can be decomposed into a sequence of weak measurements, which cause only small changes to the state. Similar constructions for generalized measurements, however, have relied on the use of an ancilla system. We show that any generalized measurement can be decomposed into a sequence of weak measurements without the use of an ancilla, and give an explicit construction for these weak measurements. The measurement procedure has the structure of a random walk along a curve in state space, with the measurement ending when one of the end points is reached. This shows that any measurement can be generated by weak measurements, and hence that weak measurements are universal. This may have important applications to the theory of entanglement.
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"abstract": "It is well known that any projective measurement can be decomposed into a\nsequence of weak measurements, which cause only small changes to the state.\nSimilar constructions for generalized measurements, however, have relied on the\nuse of an ancilla system. We show that any generalized measurement can be\ndecomposed into a sequence of weak measurements without the use of an ancilla,\nand give an explicit construction for these weak measurements. The measurement\nprocedure has the structure of a random walk along a curve in state space, with\nthe measurement ending when one of the end points is reached. This shows that\nany measurement can be generated by weak measurements, and hence that weak\nmeasurements are universal. This may have important applications to the theory\nof entanglement.",
"arxiv_id": "quant-ph/0503017",
"authors": [
"Ognyan Oreshkov",
"Todd A. Brun"
],
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"quant-ph"
],
"doi": "10.1103/PhysRevLett.95.110409",
"journal_ref": "Phys. Rev. Lett. 95, 110409 (2005)",
"title": "Weak measurements are universal",
"url": "https://arxiv.org/abs/quant-ph/0503017"
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