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2019年

Takaya Matsuura, Toshihiko Sasaki, and Masato Koashi
"Refined security proof of the round-robin differential-phase-shift quantum key distribution and its improved performance in the finite-sized case"
arXiv:1812.10916
Phys. Rev. A 99, 042303 (2019)

Ken-ichiro Yoshino, Mikio Fujiwara, Kensuke Nakata, Tatsuya Sumiya, Toshihiko Sasaki, Masahiro Takeoka, Masahide Sasaki, Akio Tajima, Masato Koashi, Akihisa Tomita
"Quantum key distribution with an efficient countermeasure against correlated intensity fluctuations in optical pulses"
arXiv:1802.06519
npj Quantum Information volume 4, Article number: 8 (2018)

Masahiro Kumazawa, Toshihiko Sasaki, Masato Koashi
"Rigorous calibration method for photon-number statistics"
arXiv:1710.00457
Optics Express 27, 5297-5313 (2019)

Akihiro Mizutani, Toshihiko Sasaki, Go Kato, Yuki Takeuchi, Kiyoshi Tamaki
"Information-theoretic security proof of differential-phase-shift quantum key distribution protocol based on complementarity"
arXiv:1703.03671
Quantum Sci. Technol. 3, 014003 (2018)

Shun Kawakami, Toshihiko Sasaki, Masato Koashi
"Finite-key analysis for quantum key distribution with weak coherent pulses based on Bernoulli sampling"
arXiv:1701.04168
Phys. Rev. A 96, 012305 (2017)

Yasunari Suzuki, Keisuke Fujii, and Masato Koashi
"Efficient simulation of quantum error correction under coherent error based on non-unitary free-fermionic formalism"
arXiv:1703.03671
Phys. Rev. Lett. 119, 190503 (2017)

Toshihiko Sasaki and Masato Koashi
"A security proof of the round-robin differential phase shift quantum key distribution protocol based on the signal disturbance"
arXiv:1701.08509
Quantum Sci. Technol. 2, 024006 (2017)

Tomoyuki Morimae, Keisuke Fujii, and Harumichi Nishimura
"Power of one non-clean qubit"
arXiv:1610.07244
Phys. Rev. A 95, 042336 (2017)

Keisuke Fujii and Masahito Hayashi
"Verifiable fault-tolerance in measurement-based quantum computation"
arXiv:1610.05216
Phys. Rev. A 96, 030301 (2017)

Keisuke Fujii
"Noise Threshold of Quantum Supremacy"
arXiv:1610.03632.

Yoshifumi Nakata, Christoph Hirche, Masato Koashi, and Andreas Winter
"Efficient unitary designs with nearly time-independent Hamiltonian dynamics"
arXiv:1609.07021
Phys. Rev. X 7, 021006 (2017).

Kais Abdelkhalek, Yoshifumi Nakata, and David Reeb
"Fundamental energy cost for quantum measurement"
arXiv:1609.06981.

Tomoyuki Morimae, Keisuke Fujii, and Harumichi Nishimura
"Quantum Merlin-Arthur with noisy channel"
arXiv:1608.04829.

Yuki Takeuchi, Keisuke Fujii, Tomoyuki Morimae, and Nobuyuki Imoto
"Practically verifiable blind quantum computation with acceptance rate amplification"
arXiv:1607.01568.

Toshihiko Sasaki, Kiyoshi Tamaki, and Masato Koashi
"Quantum key distribution protocols with slow basis choice"
arXiv:1604.04460.

Yoshifumi Nakata, Christoph Hirche, Ciara Morgan, and Andreas Winter
"Decoupling with random diagonal unitaries"
arXiv:1509.05155
Quantum 1, 18 (2017)

Yoshifumi Nakata, Christoph Hirche, Ciara Morgan, and Andreas Winter
"Unitary 2-designs from random X- and Z-diagonal unitaries"
arXiv:1502.07514,
J. Math. Phys. 58, 052203 (2017)

Keisuke Fujii, Hirotada Kobayashi, Tomoyuki Morimae, Harumichi Nishimura, Shuhei Tamate, and Seiichiro Tani
"Power of quantum computation with few clean qubits"
Proceedings of 43rd In- ternational Colloquium on Automata, Languages, and Programming (ICALP 2016), pp.13:1-13:14.

Keisuke Fujii and Shuhei Tamate
"Computational quantum-classical boundary of complex and noisy quantum systems"
Scientific Reports 6, 25598 (2016).

Shun Kawakami, Toshihiko Sasaki, and Masato Koashi
"Security of differential quadrature phase shift quantum key distribution"
Phys. Rev. A 94, 022332 (2016).

Hiroki Takesue, Toshihiko Sasaki, Kiyoshi Tamaki, and Masato Koashi
"Experimental quantum key distribution without monitoring signal disturbance"
Nature Photonics 9, 827-831 (2015).

Toshihiko Sasaki, Yoshihisa Yamamoto, and Masato Koashi
"Practical quantum key distribution protocol without monitoring signal disturbance"
Nature 509, 475-478 (2014).

Rikizo Ikuta, Hiroshi Kato, Yoshiaki Kusaka, Shigehito Miki, Taro Yamashita, Hirotaka Terai, Mikio Fujiwara, Takashi Yamamoto, Masato Koashi, Masahide Sasaki, Zhen Wang, and Nobuyuki Imoto
"High-fidelity conversion of photonic quantum information to telecommunication wavelength with superconducting single-photon detectors"
Phys. Rev. A 87, 010301(R) (2013).

Koji Azuma, Hitoshi Takeda, Masato Koashi, and Nobuyuki Imoto
"Quantum repeaters and computation by a single module: Remote nondestructive parity measurement"
Phys. Rev. A 85, 062309 (2012).

Rikizo Ikuta, Yoshiaki Kusaka, Tsuyoshi Kitano, Hiroshi Kato, Takashi
Yamamoto, Masato Koashi, and Nobuyuki Imoto
" Wide-band quantum interface for visible-to-telecommunication wavelength conversion",
Nat. Commun. 2, 537 (2011) doi: 10.1038/ncomms1544.

S. K. Ozdemir, E. Matsunaga, T. Tashima, T. Yamamoto, M. Koashi, and N. Imoto,
"An optical fusion gate for W-states",
New J. Phys. 13 103003 (2011).

Rikizo Ikuta, Yohei Ono, Toshiyuki Tashima, Takashi Yamamoto, Masato Koashi, and Nobuyuki Imoto
"Efficient decoherence-free entanglement distribution over lossy quantum channels"
Phys. Rev. Lett. 106, 110503 (2011).

Rikizo Ikuta, Toshiyuki Tashima, Takashi Yamamoto, Masato Koashi, and Nobuyuki Imoto
"Optimal local expansion of W states using linear optics and Fock states"
Phys. Rev. A 83, 012314 (2011).

Toshiyuki Tashima, Tsuyoshi Kitano, Sahin Kaya Ozdemir, Takashi Yamamoto, Masato Koashi, and Nobuyuki Imoto
"Demonstration of Local Expansion Toward Large-Scale Entangled Webs"
Phys. Rev. Lett. 105, 210503 (2010).

Koji Azuma, Naoya Sota, Masato Koashi, and Nobuyuki Imoto,
"Tight bound on coherent-state-based entanglement generation over lossy channels"
Phys. Rev. A 81, 022325 (2010).

Koji Azuma, Naoya Sota, Ryo Namiki, Sahin Kaya Ozdemir, Takashi Yamamoto, Masato Koashi, and Nobuyuki Imoto,
"Optimal entanglement generation for efficient hybrid quantum repeaters",
Phys. Rev. A 80, 060303(R) (2009).

Yoritoshi Adachi, Takashi Yamamoto, Masato Koashi, and Nobuyuki Imoto,
``Boosting up quantum key distribution by learning statistics of practical single-photon sources,"
New J. Phys. 11. 113033 (2009).

K. Tamaki, N. Lütkenhaus, M. Koashi, and J. Batuwantudawe:
"Unconditional security of the Bennett 1992 quantum-key-distribution scheme with a strong reference pulse,"
Phys. Rev. A 80, 032302 (2009).

Masato Koashi
"Simple security proof of quantum key distribution based on complementarity"
New J. Phys. 11, 045018 (2009).

Toshiyuki Tashima, Tetsuroh Wakatsuki, Sahin Kaya Ozdemir, Takashi Yamamoto, Masato Koashi, and Nobuyuki Imoto
"Local Transformation of Two Einstein-Podolsky-Rosen Photon Pairs into a Three-Photon W State"
 Phys. Rev. Lett. 102, 130502 (2009).

Kazuhiro Yokota, Takashi Yamamoto, Masato Koashi, and Nobuyuki Imoto
"Direct observation of Hardy's paradox by joint weak measurement with an entangled photon pair,"
New J. Phys. 11, 033011 (2009).
IOP press release - Quantum paradox directly observed - a milestone in quantum mechanics
New Journal of Physics - Best of 2009

M. S. Tame, S. K. Ozdemir, M. Koashi, N. Imoto, and M. S. Kim
"Compact Toffoli gate using weighted graph states,"
Phys. Rev. A 79, 020302 (2009).

Toshiyuki Tashima, Sahin Kaya Ozdemir, Takashi Yamamoto, Masato Koashi, and Nobuyuki Imoto
"Local expansion of photonic W state using a polarization dependent beamsplitter,"
New J. Phys. 11, 023024 (2009).

Ryo Namiki, Masato Koashi, and Nobuyuki Imoto
"Fidelity Criterion for Quantum-Domain Transmission and Storage of Coherent States Beyond the Unit-Gain Constraint,"
Phys. Rev. Lett. 101, 100502 (2008).

Takashi Yamamoto, Kodai Hayashi, Sahin Kaya Ozdemir, Masato Koashi and Nobuyuki Imoto
"Robust photonic entanglement distribution by state-independent encoding onto decoherence-free subspace"
Nature Photonics 2, 488 (2008).

Yuuki Tokunaga, Shin Kuwashiro, Takashi Yamamoto, Masato Koashi, and Nobuyuki Imoto
"Generation of High-Fidelity Four-Photon Cluster State and Quantum-Domain Demonstration of One-Way Quantum Computing"
Phys. Rev. Lett. 100, 210501 (2008).

Toshiyuki Tashima Sahin Kaya Ozdemir Takashi Yamamoto Masato Koashi and Nobuyuki Imoto
"Elementary optical gate for expanding an entanglement web"
Phys. Rev. A 77, 030302(R) (2008).

Yoritoshi Adachi, Takashi Yamamoto, Masato Koashi, and Nobuyuki Imoto
"Simple and Efficient Quantum Key Distribution with Parametric Down-Conversion"
Phys. Rev. Lett. 99, 180503 (2007).

Y. Kinoshita, R. Namiki, T. Yamamoto, M. Koashi, and N. Imoto:
"Selective entanglement breaking,"
Phys. Rev. A 75, 032307 (2007).

Yuuki Tokunaga, Takashi Yamamoto, Masato Koashi, and Nobuyuki Imoto:
"Fidelity estimation and entanglement verification for experimentally produced four-qubit cluster states,"
Phys. Rev. A 74, 020301(R) (2006).

Ryo Namiki, Masato Koashi, and Nobuyuki Imoto:
"Cloning and optimal Gaussian individual attacks for a continuous-variable quantum key distribution using coherent states and reverse reconciliation,"
Phys. Rev. A73, 032302 (2006).

Koji Azuma, Junichi Shimamura, Masato Koashi, and Nobuyuki Imoto:
"Probabilistic cloning with supplementary information,"
Phys. Rev. A72, 032335 (2005).

T. Yamamoto, J. Shimamura, S. K. Ozdemir, M. Koashi, and N. Imoto ,
Faithful Qubit Distribution Assisted by One Additional Qubit against Collective Noise,
Phys. Rev. Lett. 95, 040503 (2005).

Yuuki Tokunaga, Takashi Yamamoto, Masato Koashi, and Nobuyuki Imoto:
"Simple experimental scheme of preparing a four-photon entangled state for the teleportation-based realization of a linear optical controlled-NOT gate,"
Phys. Rev. A71, 030301(R) (2005).

M. Koashi:
"Unconditional security of coherent-state quantum key distribution with a strong phase-reference pulse,"
Phys. Rev. Lett. 93, 120501 (2004).