2014 Fiscal Year Annual Research Report
| Project/Area Number |
12F02019
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| Research Institution | Nagoya University |
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Principal Investigator |
小澤 正直 名古屋大学, 情報科学研究科, 教授 (40126313)
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| Co-Investigator(Kenkyū-buntansha) |
DALL'ARNO Michele 名古屋大学, 情報科学研究科, 外国人特別研究員
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| Project Period (FY) |
2012-04-01 – 2015-03-31
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| Keywords | 量子情報 / 量子通信 / 量子測定 / 量子暗号 |
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| Outline of Annual Research Achievements |
The accessible information quantifies the amount of classical information that can be extracted from an ensemble of quantum states. Analogously, the informational power quantifies the amount of classical information that can be extracted by a quantum measurement.For both quantities, we provided upper and lower bounds that depend only on the dimension of the system, and we proved their tightness. In the case of symmetric informationally complete (SIC) ensembles and measurements, we provided stronger bounds and we proved their tightness for qubits and qutrits. From our upper bounds, we noticed, perhaps surprisingly, that the statistics generated by SIC ensembles or measurements in arbitrary dimension, though optimal for tomographic purposes, in fact never contains more than just one bit of information, the rest being constituted by completely random bits. On the other hand, from our lower bounds, we obtained an explicit strategy beating the so-called "pretty-good" one for the extraction of mutual information in the case of SIC ensembles and measurements.
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| Research Progress Status |
26年度が最終年度であるため、記入しない。
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| Strategy for Future Research Activity |
26年度が最終年度であるため、記入しない。
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