Browsing by Author "Takeno, Yuishi"

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Photon-number-resolved heralded-photon source for improved quantum key distribution
(2007-07-01)
Horikiri, Tomoyuki
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Takeno, Yuishi
;
Yabushita, Atsushi
;
Kobayashi, Takayoshi
;
電子物理學系
We have suppressed multiphoton probability of a heralded-photon source, which is vital for quantum key distribution with a higher secure key generation rate. It is accomplished by utilizing a practical photon-number-resolving detector for triggering resulting in an important step for improved practical quantum key distribution. Heralded-photon source and a practical photon-number-resolving detector capable of real-time processed multiphoton rejection are stably operable at room temperature and enable us to generate a secure key at a distance as long as an ideal single photon source is used.
Purification of single qubits by collinear photons
(2007-03-01)
Odate, Satoru
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Takeno, Yuishi
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Kobayashi, Takayoshi
;
電子物理學系
;
Department of Electrophysics
We have demonstrated purification of a single qubit by two collinear photons, one of which was time-delayed. Our method can be applied to a single qubit many times, and the qubit can be purified to an arbitrarily high degree of purity. Thus, by repeating this method we can make the statistical error that single qubits incur along a transmission channel much smaller.