| 研究課題/領域番号 |
15F15015
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| 研究機関 | 名古屋大学 |
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研究代表者 |
小澤 正直 名古屋大学, 情報科学研究科, 教授 (40126313)
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| 研究分担者 |
SHUKLA Chitra 名古屋大学, 情報科学研究科, 外国人特別研究員
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| 研究期間 (年度) |
2015-04-24 – 2017-03-31
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| キーワード | Quantum Communication / Quantum Cryptography / Entangled States / Hierarchical Commun. / Quantum Noise / Quantum Circuit / Entanglement Concent. |
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| 研究実績の概要 |
The main study of the research plan was to develop the new protocols of secure quantum communication, which have practical significance.
1. We proposed two entanglement concentration protocols (ECPs) for a set of (n+1)-qubit states using linear optics and cross-kerr-nonlinearity (QND). The maximum success probability 2β^2 is obtained (using QND). The quantum circuits are also designed using linear optics, which can be experimentally realizable using present technologies.
2. A new “Hierarchical Joint Remote State Preparation” (HJRSP) has been proposed to achieve the secret communication in a multiparty scheme where two senders jointly prepare a known quantum state at receiver's end. Further, HJRSP is investigated under various quantum noises and calculated the average fidelity writing codes in “Mathematica” to analyze the robustness of the scheme.
3. A quantum circuit using Controlled SWAP (CSWAP) quantum gates is designed to solve the problem of permutation of particles (PoP) for the orthogonal-state-based protocols.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
1. Two practical schemes for entanglement concentration protocols (ECPs) are achieved for a set of entangled states of a particular form, and the same is reported and already published in an International Journal, “Quantum Information Processing” (QINP).
2. The study on Hierarchical Joint Remote State Preparation (HJRSP) had been completed and ready to be communicated next week to the International Journal.
3. Regarding the designed quantum circuit for permutation of particles (PoP), some more important discussions would be needed to accomplish the work as a full paper. Hence, this study would be reported in the next year.
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| 今後の研究の推進方策 |
1. To study and design the single particle based secure quantum communication protocol (QKD) and investigate its security under the universally valid uncertainty relations.
2. To design unconditionally secure protocols of semi-quantum communication (such as semi-quantum key agreement (SQKA), semi-qunatum dialogue (SQD), semi-hierarchical quantum communication, etc.) with optimal/minimal nonclassical resources, which will show less quantum resources are required than the existing fully quantum protocols because in semi-quantum cryptography, one of the users is classical.
3. The device independence would be studied using Kochen-Specker theorem or Leggett-Garg inequality for designing of the new protocol.
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