dorsal/arxiv
View SchemaDistinguishing mixed quantum states: Minimum-error discrimination versus optimum unambiguous discrimination
| Authors | Ulrike Herzog, Janos A. Bergou |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0403124 |
| URL | https://arxiv.org/abs/quant-ph/0403124 |
| DOI | 10.1103/PhysRevA.70.022302 |
Abstract
We consider two different optimized measurement strategies for the discrimination of nonorthogonal quantum states. The first is conclusive discrimination with a minimum probability of inferring an erroneous result, and the second is unambiguous, i. e. error-free, discrimination with a minimum probability of getting an inconclusive outcome, where the measurement fails to give a definite answer. For distinguishing between two mixed quantum states, we investigate the relation between the minimum error probability achievable in conclusive discrimination, and the minimum failure probability that can be reached in unambiguous discrimination of the same two states. The latter turns out to be at least twice as large as the former for any two given states. As an example, we treat the case that the state of the quantum system is known to be, with arbitrary prior probability, either a given pure state, or a uniform statistical mixture of any number of mutually orthogonal states. For this case we derive an analytical result for the minimum probability of error and perform a quantitative comparison to the minimum failure probability.
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"abstract": "We consider two different optimized measurement strategies for the\ndiscrimination of nonorthogonal quantum states. The first is conclusive\ndiscrimination with a minimum probability of inferring an erroneous result, and\nthe second is unambiguous, i. e. error-free, discrimination with a minimum\nprobability of getting an inconclusive outcome, where the measurement fails to\ngive a definite answer. For distinguishing between two mixed quantum states, we\ninvestigate the relation between the minimum error probability achievable in\nconclusive discrimination, and the minimum failure probability that can be\nreached in unambiguous discrimination of the same two states. The latter turns\nout to be at least twice as large as the former for any two given states. As an\nexample, we treat the case that the state of the quantum system is known to be,\nwith arbitrary prior probability, either a given pure state, or a uniform\nstatistical mixture of any number of mutually orthogonal states. For this case\nwe derive an analytical result for the minimum probability of error and perform\na quantitative comparison to the minimum failure probability.",
"arxiv_id": "quant-ph/0403124",
"authors": [
"Ulrike Herzog",
"Janos A. Bergou"
],
"categories": [
"quant-ph"
],
"doi": "10.1103/PhysRevA.70.022302",
"title": "Distinguishing mixed quantum states: Minimum-error discrimination versus optimum unambiguous discrimination",
"url": "https://arxiv.org/abs/quant-ph/0403124"
},
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