Publications

(T. S. Usuda)


Journal Papers


  1. S. Bun, T. Sasaki, H. Tsushima, O. Hirota, and M. Nakagawa,
    A realization of optical communication using received quantum state control,
    The transaction of the IEICE, vol.E73, no.10, pp.1647-1656, (1990.10).

  2. T. Sasaki and O. Hirota,
    An optical receiver overcome the standard quantum limit,
    IEICE Transactions on Communications, vol.E75-B, no.6, pp.514-520, (1992.6).

  3. T. S. Usuda, T. Satoh, K. Yamazaki, and O. Hirota,
    Signal-to-noise ratio of optical system consisting of squeezer and optical Kerr medium,
    Journal of Modern Optics, Special Issue on Quantum Communication, vol.41, no.12, pp.2275-2289, (1994.12). doi: 10.1080/09500349414552131

  4. M. Sasaki, T. S. Usuda, and O. Hirota,
    Physical aspect of improvement of quantum noise characteristics caused by unitary transformation with nonlinear optical medium,
    Physical Review, vol.A51, no.2, pp.1702-1705, (1995.2). doi: 10.1103/PhysRevA.51.1702

  5. M. Sasaki, T. S. Usuda, O. Hirota, and A. S. Holevo,
    Applications of the Jaynes-Cummings model for the detection of nonorthogonal quantum states,
    Physical Review, vol.A53, no.3, pp.1273-1279, (1996.3). doi: 10.1103/PhysRevA.53.1273

  6. M. Sasaki, T. S. Usuda, M. Izutsu, and O. Hirota,
    Realization of a collective decoding of codeword states,
    Physical Review, vol.A58, no.1, pp.159-164, (1998.7). doi: 10.1103/PhysRevA.58.159

  7. M. Osaki, T. S. Usuda, and O. Hirota,
    Group covariant detection for a three-phase shift keyed signal,
    Physics Letters, vol.A245, pp.189-196, (1998.8). doi: 10.1016/S0375-9601(98)00409-5

  8. T. S. Usuda, I. Takumi, M. Hata, and O. Hirota,
    Minimum error detection of classical linear code sending through a quantum channel,
    Physics Letters, vol.A256, pp.104-108, (1999.5). doi: 10.1016/S0375-9601(99)00232-7

  9. T. Kudo, T. S. Usuda, I. Takumi, and M. Hata,
    Application of quantum cryptography to an eavesdropping detectable data transmission,
    IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Special Section on Information Theory and Its Applications, vol.E82-A, no.10, pp.2178-2184, (1999.10).

  10. S. Usami, T. S. Usuda, I. Takumi, and M. Hata,
    A simplification algorithm for calculation of the mutual information by quantum combined measurement,
    IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Special Section on Information Theory and Its Applications, vol.E82-A, no.10, pp.2185-2190, (1999.10).

  11. Y. Fujihara, T. S. Usuda, I. Takumi, and M. Hata,
    Relation between optimum quantum detection operators for pure and mixed-state signals,
    IEICE Transactions, vol.J84-A, no.1, pp.63-72, (2001.1) (in Japanese).
    English translation : Electronics and Communications in Japan: Part III, vol.86 (10), pp.8-18 , John Wiley & Sons, (2003). doi: 10.1002/ecjc.1153

  12. Y. Fujihara, S. Tatsuta, T. S. Usuda, I. Takumi, and M. Hata,
    Realization of quantum receiver for M-ary signals,
    IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Special Section on Fundamentals of Information and Communications, vol.E84-A, no.4, pp.906-912, (2001.4).

  13. T. S. Usuda, S. Usami, I. Takumi, and M. Hata,
    Superadditivity in capacity of quantum channel for q-ary linearly dependent real symmetric-state signals,
    Physics Letters A, vol.A305, pp.125-134, (2002.11). doi: 10.1016/S0375-9601(02)01413-5

  14. Y. Ishida, S. Usami, T. S. Usuda, and I.Takumi,
    Properties of quantum gain of coding with information criterion by binary linear codes,
    IEEJ Transactions on Electronics, Information and Systems, vol.126, no.12, pp.1474-1482, (2006.12) (in Japanese). doi: 10.1541/ieejeiss.126.1474
    English translation : Electrical Engineering in Japan, vol.163, no.4, pp.48-57 , Wiley Periodicals, inc., (2008). doi: 10.1002/eej.20646

  15. R. Yamamoto, S. Hattori, T. S. Usuda, and I. Takumi,
    Entanglement of formation of a quasi-Bell state with non-symmetric loss,
    IEEJ Transactions on Electronics, Information and Systems, vol.126, no.12, pp.1531-1532, (2006.12) (in Japanese). doi: 10.1541/ieejeiss.126.1531

  16. H. Nanjo, T. Ohashi, T. S. Usuda, and I. Takumi,
    Application of quantum error correcting code for specific position errors to quantum protocol,
    IEEJ Transactions on Electronics, Information and Systems, vol.126, no.12, pp.1535-1536, (2006.12) (in Japanese). doi: 10.1541/ieejeiss.126.1535

  17. H. Nanjo, T. S. Usuda, and I. Takumi,
    Purification of the quasi-Bell state from (3,1) quantum error correcting code,
    IEEJ Transactions on Electronics, Information and Systems, vol.128, no.12, pp.1741-1742, (2008.12) (in Japanese). doi: 10.1541/ieejeiss.128.1741

  18. R. Sahara, Y. Hayashi, S. Usami, T. S. Usuda, and I. Takumi,
    An example of code that has quantum gain with two criteria,
    IEEJ Transactions on Electronics, Information and Systems, vol.128, no.12, pp.1743-1744, (2008.12) (in Japanese). doi: 10.1541/ieejeiss.128.1743

  19. A. Imaeda, M. Yoshikawa, and T. S. Usuda,
    Improvement of quasi-optimum quantum receiver for 3-PSK coherent-state signals,
    IEEJ Transactions on Electronics, Information and Systems, vol.129, no.12, pp.2159-2160, (2009.12) (in Japanese). doi: 10.1541/ieejeiss.129.2159

  20. S. Yamaguchi, T. S. Usuda, and I. Takumi,
    Quantum probabilistic teleportation using a quasi-Bell state degraded by asymmetric energy loss,
    IEEJ Transactions on Electronics, Information and Systems, vol.129, no.12, pp.2161-2162, (2009.12) (in Japanese). doi: 10.1541/ieejeiss.129.2161

  21. T. Sawada and T. S. Usuda,
    Pseudo-classicality of square-root measurement,
    IEEJ Transactions on Electronics, Information and Systems, vol.129, no.12, pp.2174-2179, (2009.12) (in Japanese). doi: 10.1541/ieejeiss.129.2174

  22. Y. Asami, Y. Hattori, R. Sahara, and T. S. Usuda,
    Comparison of capacities for 3ASK squeezed-state and coherent-state signals,
    IEEJ Transactions on Electronics, Information and Systems, vol.130, no.1, pp.154-155, (2010.1) (in Japanese). doi: 10.1541/ieejeiss.130.154

  23. M. Ota, K. Shiromoto, T. S. Usuda,
    Analytical solution of channel matrix for coded quantum signals by arbitrary classical linear codes over the ring of integers,
    IEICE Transactions, vol.J95-B, no.2, pp.110-118, (2012.2) (in Japanese).

  24. K. Nakahira and T. S. Usuda,
    Minimum-error discrimination between self-symmetric mixed quantum state signals,
    IEEE Transactions on Information Theory, vol.58, no.2, pp.1215-1222, (2012.2). doi: 10.1109/TIT.2011.2170954

  25. K. Nakahira, T. S. Usuda, and K. Kato,
    Discrimination between geometrically uniform quantum states with inconclusive results,
    Physical Review, vol.A86, no.3, 032316, (2012.9). doi: 10.1103/PhysRevA.86.032316

  26. K. Nakahira and T. S. Usuda,
    Optimal receiver for discrimination of two coherent states with inconclusive results,
    Physical Review, vol.A86, no.5, 052323, (2012.11). doi: 10.1103/PhysRevA.86.052323

  27. K. Nakahira and T. S. Usuda,
    Minimum Bayes-cost discrimination for symmetric quantum states,
    Physical Review, vol.A86, no.6, 062305, (2012.12). doi: 10.1103/PhysRevA.86.062305

  28. K. Nakahira, T. S. Usuda, and K. Kato,
    A geometric interpretation of optimal inconclusive measurements and their derivation processes,
    IEICE Transactions, vol.J96-A, no.1, pp.56-66, (2013.1) (in Japanese).

  29. K. Nakahira and T. S. Usuda,
    Quantum measurement for group covariant state set,
    Physical Review, vol.A87, no.1, 012308, (2013.1). doi: 10.1103/PhysRevA.87.012308

  30. K. Nakahira K. Kato, and T. S. Usuda,
    Minimax strategy in quantum signal detection with inconclusive results,
    Physical Review A, vol.A88, no.3, 032314, (2013.9). doi: 10.1103/PhysRevA.88.032314

  31. H. Takeuchi, S. Yamaguchi, and T. S. Usuda,
    Optimizing encodings and property of capacity in classical communication assisted by a quasi-Bell state,
    IEEJ Transactions on Electronics, Information and Systems, vol.133, no.12, pp.2176-2177, (2013.12) (in Japanese). doi: 10.1541/ieejeiss.133.2176

  32. K. Nakahira and T. S. Usuda,
    Implementation of non-projective measurements on a Hilbert space spanned by binary coherent states,
    Physical Review, vol.A89, no.1, 012120, (2014.1). doi: 10.1103/PhysRevA.89.012120

  33. K. Nakahira, K. Kato, and T. S. Usuda,
    Iterative methods for finding optimal quantum measurements under minimum-error and minimax criteria,
    Physical Review, vol.A91, no.1, 012318, (2015.1). doi: 10.1103/PhysRevA.91.012318

  34. K. Nakahira, T. S. Usuda, and K. Kato,
    Finding optimal measurement with inconclusive results using the problem of minimum error discrimination,
    Physical Review, vol.A91, no.2, 022331, (2015.2). doi: 10.1103/PhysRevA.91.022331

  35. K. Nakahira, K. Kato, and T. S. Usuda,
    Generalized quantum state discrimination problems,
    Physical Review, vol.A91, no.5, 052304, (2015.5). doi: 10.1103/PhysRevA.91.052304
    arXiv:1501.05744v2 [quant-ph]

  36. A. Ohashi, T. S. Usuda, T. Sogabe, and F. Yilmaz,
    On tensor product decomposition of k-tridiagonal Toeplitz matrices,
    International Journal of Pure and Applied Mathematics, vol.103, no.3, pp.537-545, (2015.8). doi: 10.12732/ijpam.v103i3.14

  37. A. Ohashi, T. Sogabe, and T. S. Usuda,
    On decomposition of k-tridiagonal l-Toeplitz matrices and its applications,
    Special Matrices, vol.3, pp.200-206, (2015.10). doi: 10.1515/spma-2015-0019

  38. A. Ohashi, T. Sogabe, and T. S. Usuda,
    Fast block diagonalization of (k,k')-pentadiagonal matrices,
    International Journal of Pure and Applied Mathematics, vol.106, no.2, pp.513-523, (2016.2). doi: 10.12732/ijpam.v106i2.14

  39. S. Mizuno, Y. Moriizumi, T. S. Usuda, and T. Sogabe,
    An initial guess of Newton's method for the matrix square root based on a sphere constrained optimization problem,
    JSIAM Letters, vol.8, pp.17-20, (2016.3).

  40. K. Nakahira, T. S. Usuda, and K. Kato,
    Finding optimal solutions for generalized quantum state discrimination problems,
    IEEE Transactions on Information Theory, vol.63, no.12, pp.7845-7856, (2017.12). doi: 10.1109/TIT.2016.2644666
    arXiv:1510.05202 [quant-ph]

  41. K. Nakahira and T. S. Usuda,
    Realizing a 2-D positive operator-valued measure by local operations and classical communication,
    IEEE Transactions on Information Theory, vol.64, no.1, pp.613-621, (2018.1). doi: 10.1109/TIT.2016.2549994
    arXiv:1501.06222 [quant-ph]

  42. K. Nakahira, T. S. Usuda and K. Kato,
    Upper and lower bounds on optimal success probability of quantum state discrimination with and without inconclusive results,
    Physical Review, vol.A97, 012103, (2018.1). doi: 10.1103/PhysRevA.97.012103
    arXiv:1601.06231v2 [quant-ph]

  43. [Editors' Suggestion] K. Nakahira, K. Kato, and T. S. Usuda,
    Optimal discrimination of optical coherent states cannot always be realized by interfering with coherent light, photon counting, and feedback,
    Physical Review, vol.A97, 022320, (2018.2). doi: 10.1103/PhysRevA.97.022320
    arXiv:1601.06231v2 [quant-ph]

  44. K. Nakahira, K. Kato, and T. S. Usuda,
    Generalized bipartite quantum state discrimination problems with sequential measurements,
    Physical Review, vol.A97, 022340, (2018.2). doi: 10.1103/PhysRevA.97.022340
    arXiv:1707.04736 [quant-ph]

  45. M. Tanaka, A. Ohashi, S. Takahira, T. S. Usuda,
    Symmetrization method of 3-ary ASK coherent-state signals by using coding,
    IEICE Transactions, vol.J101-B, no.11, pp.978-987, (2018.11) (in Japanese). doi: 10.14923/transcomj.2017JBP3065

  46. S. Takahira, T. Sogabe, and T. S. Usuda,
    Bidiagonalization of (k, k+1)-tridiagonal matrices,
    Special Matrices, (2019.1). doi: 10.1515/spma-2019-0002

  47. K. Nakahira, K. Kato, and T. S. Usuda,
    Local unambiguous discrimination of symmetric ternary states,
    Physical Review, vol.A99, 022316, (2019.2). doi: 10.1103/PhysRevA.99.022316
    arXiv:1806.08784 [quant-ph]

  48. S. Takahira, A. Ohashi, T. Sogabe, and T. S. Usuda,
    Quantum algorithm for matrix functions by Cauchy's integral formula,
    Quantum Information and Computation, vol.20, no.1&2, pp.14-36, (2020.1). doi: 10.26421/QIC20.1-2

  49. K. Ishikawa, T. Wang, and T. S. Usuda,
    Comparison of performances on quantum reading in non-symmetric loss using maximum and non-maximum quasi-Bell states,
    IEEJ Transactions on Electronics, Information and Systems, vol.140, no.12, pp.1328-1335, (2020.12) (in Japanese). doi: 10.1541/ieejeiss.140.1328

  50. T. Wang, S. Takahira, T. S. Usuda,
    Error probabilities of quantum illumination with attenuation using maximum and non-maximum quasi-Bell states,
    IEEJ Transactions on Electronics, Information and Systems, vol.142, no.2, pp.151-161, (2022.2) (in Japanese). doi: 10.1541/ieejeiss.142.151

  51. T. Wang, S. Koyama, K. Nakahira, T. S. Usuda,
    Error performances and robust design criteria for quantum receiver in the presence of phase noise,
    IEICE Transactions, vol.J105-B, no.3, pp.39-51, (2022.3) (in Japanese). doi: 10.14923/transcomj.2021GWP0028

  52. S. Isokawa, R. Nakagawa, T. Wang, S. Takahira, T. S. Usuda,
    Geometric representation of the Belavkin weighted square-root measurement for pure-state signals,
    IEICE Transactions, vol.J105-B, no.3, pp.62-73, (2022.3) (in Japanese). doi: 10.14923/transcomj.2021GWP0030

  53. R. Miyazaki, M. Yoshida, T. Wang, S. Takahira, T. S. Usuda,
    Simplification of calculation of channel matrix for non-symmetric signals,
    IEICE Transactions, vol.J105-B, no.3, pp.74-87, (2022.3) (in Japanese). doi: 10.14923/transcomj.2021GWP0032

  54. R. Miyazaki, T. Wang, and T. S. Usuda,
    Simplification of the Gram matrix eigenvalue problem for quadrature amplitude modulation signals,
    Entropy, Special Issue "Quantum Communication, Quantum Radar, and Quantum Cipher", vol.24, issue4, 544, (2022.4). doi: 10.3390/e24040544

  55. T. Wang and T. S. Usuda,
    Error performance of amplitude shift keying-type asymmetric quantum communication system,
    Entropy, Special Issue "Quantum Communication, Quantum Radar, and Quantum Cipher", vol.24, issue5, 708, (2022.5). doi: 10.3390/e24050708

  56. Y. Takahashi, T. Wang, S. Usami, and, T. S. Usuda,
    Effect of multiple positions illumination in quantum ghost imaging,
    IEEJ Transactions on Electronics, Information and Systems, vol.142, no.8, pp.933-941, (2022.8) (in Japanese). doi: 10.1541/ieejeiss.142.933

  57. S. Takahira, A. Ohashi, T. Sogabe, and T. S. Usuda,
    Quantum Algorithms based on the block-encoding framework for matrix functions by contour integrals,
    Quantum Information and Computation, vol.22, no.11&12, pp.965-979, (2022.9). doi: 10.26421/QIC22.11-12-4

  58. T. Wang, R. Miyazaki, S. Takahira, T. S. Usuda,
    Simplification of the Gram matrix eigenvalue problem for quantum signals formed by rotating signal points in a circular sector region,
    IEEJ Transactions on Electronics, Information and Systems, vol.142, no.12, pp.1253-1261, (2022.12) (in Japanese). doi: 10.1541/ieejeiss.142.1253

  59. S. Sameshima, T. Wang, S. Usami, and T. S. Usuda,
    A PSK-type asymmetric quantum communication and its error performance in attenuated environments,
    IEICE Transactions, vol.J106-B, no.3, pp.112-125, (2023.3) (in Japanese). doi: 10.14923/transcomj.2022GWP0018

  60. T. Wang and T. S. Usuda,
    Simple detection scheme and performance evaluation for quantum illumination using quasi-Bell state,
    IEEJ Transactions on Electronics, Information and Systems, vol.143, no.12, pp.1090-1098, (2023.12) (in Japanese). doi: 10.1541/ieejeiss.143.1090

  61. [Editor's Pick] T. Wang and T. S. Usuda,
    Detection scheme using a beam splitter and on-off detectors for non-Gaussian state-based quantum illumination with attenuation,
    Optics Continuum, vol.3, issue4, pp.543-551, (2024.3). doi: 10.1364/OPTCON.514321


International Conferences


(1990-1995)

    1. S. Bun and T. Sasaki,
      Properties of system using spatial multi-mode squeezer,
      1990 Workshop on Quantum Aspects of Optical Communications, Paris, France, Abstacts of Papers, pp.43-45 (1990.11).
      in Quantum Aspects of Optical Communications, Lecture Notes in Physics 378, C. Bendjaballah, O. Hirota, and S. Reynaud (Eds.), Springer-Verlag Berlin, pp.239-248, (1991).

    2. T. Sasaki and O. Hirota,
      A realization of quantum state switch,
      1992 International symposium on information theory and its applications, Singapore, Proceedings of ICCS/ISITA'92, vol.1, pp.219-223, (1992.11).

    3. T. Sasaki, S. Noppanakeepong, O. Hirota, and S. Tsujii,
      Effect of complex nonlinear susceptibility in generation of squeezed state light,
      1992 International symposium on information theory and its applications, Singapore, Proceedings of ICCS/ISITA'92, vol.1, pp.224-227, (1992.11).

    4. T. Sasaki, T. Sato, N. Ubayama, K. Yamazaki, and O. Hirota,
      Elimination of nonlinear PM and FM noises in optical amplifier repeater systems by squeezer,
      SPIE's 1993, San Diego, California USA, Proceedings of SPIE, vol.2024, pp.52-59, (1993.7).

    5. T. S. Usuda and O. Hirota,
      An example of a received quantum state controller by optical Kerr effect,
      International Workshop on Quantum communications and Measurement, Nottingham, United Kingdom, Abstracts of Papers of QCM'94, p.72 (1994.7).
      in Quantum Communications and Measurement, V. P. Belavkin, O. Hirota, and R. L. Hudson (Eds.), Plenum Press, New York, pp.419-427, (1995).

    6. S. Noppanakeepong, T. S. Usuda, O. Hirota, K. Sakaniwa, and S. Tsujii,
      A design of squeezed light generator by control of complex nonlinear susceptibility,
      International Workshop on Quantum communications and Measurement, Nottingham, United Kingdom, Abstracts of Papers of QCM'94, p.106 (1994.7).

(1996-2001)
    1. T. S. Usuda and M. Hata,
      On the realization of received quantum state control by unitary transformation,
      Third International Conference on Quantum communication & Measurement, Mt. Fuji-Hakone Land, Japan, Abstracts of Papers of QCM'96, pp.99-100 (1996.9).
      in Quantum Communication, Computing and Measurement, O. Hirota, A. S. Holevo, and H. P. Yuen (Eds.), Plenum Press, New York, pp.127-137, (1997).

    2. T. S. Usuda and I. Takumi,
      Group covariant signals in quantum information theory,
      Fourth International Conference on Quantum Communication, Measurement, and Computing, Northwestern University, Evanston, Illinois, USA, Abstracts of Papers of QCM'98, p.51, (1998.8).
      in Quantum Communication, Computing, and Measurement 2, P. Kumar, G. M. D'Ariano, and O. Hirota (Eds.), Plenum Press, New York, pp.37-42, (2000).

    3. T. Kudo, T. S. Usuda, I. Takumi, and M. Hata,
      Eavesdropping detectable data transmission by applying quantum cryptography,
      Joint Workshop on Information Security and Cryptology 2000 (JW-ISC2000), Naha, Okinawa, Japan, Proceedings of JW-ISC2000, pp.151-158, (2000.1).

    4. S. Usami, T. S. Usuda, I. Takumi, R. Nakano, and M. Hata,
      Superadditivity in capacity of quantum channel by classical pseudo-cyclic codes,
      Fifth International Conference on Quantum Communication, Measurement, and Computing, Capri, Itary, Abstracts of Papers of QCM&C-Y2K, pp.90-91, (2000.7).
      in Quantum Communication, Computing, and Measurement 3, P. Tombesi and O. Hirota (Eds.), Plenum Press, New York, pp.35-38, (2001).

    5. T. S. Usuda, M. Osaki, I. Takumi, R. Nakano, and M. Hata,
      Property of mutual information for M-ary quantum-state signals,
      Fifth International Conference on Quantum Communication, Measurement, and Computing, Capri, Itary, Abstracts of Papers of QCM&C-Y2K, pp.92-93, (2000.7).
      in Quantum Communication, Computing, and Measurement 3, P. Tombesi and O. Hirota (Eds.), Plenum Press, New York, pp.39-42, (2001).

    6. Y. Fujihara, T. S. Usuda, I. Takumi, R. Nakano, and M. Hata,
      Realization of optimum quantum receiver for M-ary signals,
      2000 International Symposium on Information Theory and Its Applications (ISITA2000), Honolulu, Hawaii, Proceedings of ISITA2000, vol.1, pp.413-416, (2000.11).

    7. S. Tatsuta, T. S. Usuda, I. Takumi, R. Nakano, and M. Hata,
      Quantum measurement and universal gates for Schrodinger cat states as qubit,
      2000 International Symposium on Information Theory and Its Applications (ISITA2000), Honolulu, Hawaii, Proceedings of ISITA2000, vol.1, pp.417-420, (2000.11).

    8. S. Usami, K. Itoh, T. S. Usuda, I. Takumi, R. Nakano, and M. Hata,
      A study on maximization of mutual information for extension of binary quantum signals,
      2000 International Symposium on Information Theory and Its Applications (ISITA2000), Honolulu, Hawaii, Proceedings of ISITA2000, vol.1, pp.421-424, (2000.11).

(2002)
    1. S. Usami, T. S. Usuda, I. Takumi, and M. Hata,
      Error Performance for Binary Code with Mixed Letter States,
      2002 International Symposium on Information Theory and Its Applications (ISITA2002), Xi'an, China, Proceedings of ISITA2002, pp.339-342, (2002.10).

    2. Y. Hayashi, S. Usami, T. S. Usuda, and I. Takumi,
      Quantum coding gain with error probability criterion for binary linear codes,
      2002 International Symposium on Information Theory and Its Applications (ISITA2002), Xi'an, China, Proceedings of ISITA2002, pp.475-478, (2002.10).

(2003)
    1. O. Hirota, K. Kato, M. Sohma, and T. S. Usuda,
      Quantum key distribution with unconditinal security for all optical fiber network,
      Quantum Communications and Quantum Imaging, San Diego, USA, Proceedings of SPIE, no-5161, (2003.8).

    2. H. Shiraki, S. Usami, T. S. Usuda, and I. Takumi,
      Quantum error correcting code for specific position errors and its application,
      ERATO Conference on Quantum Information Science 2003 (EQIS2003), Kyoto, Japan, Proceedings of EQIS2003, pp.111-112, (2003.9).

(2004)
    1. S. Usami and T. S. Usuda,
      Quantum error correcting code for specific position errors and its capability,
      International Symposium on Quantum Info-Communications and Related Quantum Nanodevices, Toyko, Japan, p.51, (2004.3).

    2. T. S. Usuda,
      Quantum coding gain with error probability and information criteria,
      International Symposium on Quantum Info-Communications and Related Quantum Nanodevices, Toyko, Japan, p.51, (2004.3).

    3. T. S. Usuda, T. Tomari, and S. Usami,
      `Pure' square-root measurement and its optimality for mixed-state signals,
      The Seventh International Conference on Quantum Communication, Measurement and Computing (QCMC2004), Glasgow, UK, Abstracts of Papers of QCMC2004, P1.11, (2004.7).
      in Quantum Communication, Measurement and Computing, AIP Conference Proceedings, vol.734, S. M. Barnett, E. Andersson, J. Jeffers, P. Ohberg, and O. Hirota (Eds.), American Institute of Physics, New York, pp.107-110, (2004).

    4. S. Usami, H. Shiraki, T. S. Usuda, and I. Takumi,
      Construction of quantum error correcting code for specific position errors,
      The Seventh International Conference on Quantum Communication, Measurement and Computing (QCMC2004), Glasgow, UK, Abstracts of Papers of QCMC2004, P2.10, (2004.7).
      in Quantum Communication, Measurement and Computing, AIP Conference Proceedings, vol.734, S. M. Barnett, E. Andersson, J. Jeffers, P. Ohberg, and O. Hirota (Eds.), American Institute of Physics, New York, pp.191-194, (2004).

    5. O. Hirota, K. Kato, M. Sohma, and T. S. Usuda, K. Hirasawa,
      Quantum stream cipher based on optical communications,
      Quantum Communications and Quantum Imaging, San Diego, USA, Proceedings of SPIE Vol.5551-37, (2004.8).

    6. T. Mizuno, T. S. Usuda, and I. Takumi,
      Effect of entangled inputs on attenuated channel with memory,
      ERATO Conference on Quantum Information Science 2004 (EQIS2004), Tokyo, Japan, Proceedings of EQIS2004, pp.134-135, (2004.9).

    7. N. Takatsu, T. S. Usuda, and I. Takumi,
      Application of quantum gates for coherent-state qubits to quantum communications,
      ERATO Conference on Quantum Information Science 2004 (EQIS2004), Tokyo, Japan, Proceedings of EQIS2004, pp.179-180, (2004.9).

    8. T. Tomari, S. Usami, and T. S. Usuda,
      Relation between structure of codes and their optimum quantum decoding,
      ERATO Conference on Quantum Information Science 2004 (EQIS2004), Tokyo, Japan, Proceedings of EQIS2004, pp.185-186, (2004.9).

    9. T. Tomari, S. Usami, and T. S. Usuda,
      A study on optimum quantum decoding for binary linear codes with mixed letter-states,
      2004 International Symposium on Information Theory and Its Applications (ISITA2004), Parma, Italy, Proceedings of ISITA2004, pp.1429-1434, (2004.10).

    10. N. Takatsu, T. S. Usuda, and I. Takumi,
      Property of elementary gates for coherent-state qubits and their applicability to quantum communications,
      2004 International Symposium on Information Theory and Its Applications (ISITA2004), Parma, Italy, Proceedings of ISITA2004, pp.1435-1439, (2004.10).

(2005)
    1. O. Hirota, T. S. Usuda, and M. Fuse,
      Quantum stream cipher Part III: Design of keyed randomization and experiment,
      Quantum Communications and Quantum Imaging III, San Diego, USA, Proceedings of SPIE, Vol.5893-04, (2005.8).

    2. S. Hattori, T. Mizuno, and T. S. Usuda,
      Comparison of capacities of an optical channel assisted by orthogonal entangled states and two-mode squeezed states,
      ERATO Conference on Quantum Information Science 2005 (EQIS2005), Tokyo, Japan, Proceedings of EQIS2005, pp.93-94, (2005.8).

    3. R. Yamamoto, T. S. Usuda, and I. Takumi,
      Properties of nonideal quasi-Bell states : alignment mismatch and decoherence,
      ERATO Conference on Quantum Information Science 2005 (EQIS2005), Tokyo, Japan, Proceedings of EQIS2005, pp.193-194, (2005.8).

(2006)
    1. T. Tsuchimoto, T. Sawada, S. Usami, T. S. Usuda, and I. Takumi,
      Property of optimum quantum detection for mixed states with non Gaussian and Gaussian noise,
      2006 International Symposium on Information Theory and Its Applications (ISITA2006), Seoul, Korea, Proceedings of ISITA2006, pp.750-753, (2006.10-11).

    2. S. Hattori and T. S. Usuda,
      Characteristics of classical capacity of an attenuated channel assisted by orthogonal entangled states,
      2006 International Symposium on Information Theory and Its Applications (ISITA2006), Seoul, Korea, Proceedings of ISITA2006, pp.754-758, (2006.10-11).

    3. R. Yamamoto, T. S. Usuda, and I. Takumi,
      Entanglement of formation of a decohered quasi-Bell state,
      2006 International Symposium on Information Theory and Its Applications (ISITA2006), Seoul, Korea, Proceedings of ISITA2006, pp.864-867, (2006.10-11).

    4. Y. Ishida, K. Kato, and T. S. Usuda,
      Capacity of attenuated channel with discrete-valued input,
      The Eighth International Conference on Quantum Communication, Measurement and Computing (QCMC2006), Tsukuba, Japan, Abstracts of Papers of QCMC2006, p.94, (2006.11-12).
      Proceedings of the 8th International Conference on Quantum Communication, Measurement and Computing, O. Hirota, J. H. Shapiro, and M. Sasaki (Eds.), NICT Press, pp.323-326, (2007).

    5. T. Sawada, T. Tsuchimoto, and T. S. Usuda,
      Quantum detection of artificial mixed-state signals,
      The Eighth International Conference on Quantum Communication, Measurement and Computing (QCMC2006), Tsukuba, Japan, Abstracts of Papers of QCMC2006, p.168, (2006.11-12).
      Proceedings of the 8th International Conference on Quantum Communication, Measurement and Computing, O. Hirota, J. H. Shapiro, and M. Sasaki (Eds.), NICT Press, pp.405-408, (2007).

(2007)
    1. T. Sawada and T. S. Usuda,
      Quantum detection of binary symmetric mixed-state signals,
      Asian Conference on Quantum Information Science 2007 (AQIS2007), Kyoto, Japan, Proceedings of AQIS2007, pp.149-150, (2007.9).

    2. H. Nanjo, T. S. Usuda, and I. Takumi
      Entanglement purification protocol from (3,1) quantum error correcting codes for quasi-Bell states by coherent states,
      Asian Conference on Quantum Information Science 2007 (AQIS2007), Kyoto, Japan, Proceedings of AQIS2007, pp.159-160, (2007.9).

    3. S. Hirosawa, S. Usami, T. S. Usuda, and A. Ogawa,
      Property of reliability function for attenuated channel with discrete-valued input,
      Asian Conference on Quantum Information Science 2007 (AQIS2007), Kyoto, Japan, Proceedings of AQIS2007, pp.161-162, (2007.9).

(2008)
    1. T. Sawada and T. S. Usuda,
      Pseudo-classicality of square-root measurement,
      The Nineth International Conference on Quantum Communication, Measurement and Computing (QCMC2008), Calgary, Canada, Abstracts of Papers of QCMC2008, p.116, (2008.8).

    2. R. Sahara, S. Usami, and T. S. Usuda,
      The multiple coding gain with two criteria in an attenuated quantum channel,
      2008 International Symposium on Information Theory and Its Applications (ISITA2008), Auckland, New Zealand, Proceedings of ISITA2008, pp.473-478, (2008.12). doi: 10.1109/ISITA.2008.4895459

(2009)
    1. S. Yamaguchi, T. S. Usuda, and I. Takumi,
      Improvement of the probability of sharing entangled states in two-way entanglement purification protocols,
      Asian Conference on Quantum Information Science 2009 (AQIS2009), Nanjing, China, Proceedings of AQIS2009, pp.196-197, (2009.8).

    2. R. Sahara, K. Iyoda, S. Usami, and T. S. Usuda,
      Quantum gain of coding for M-ary quantum signals by good classical error correcting codes,
      Asian Conference on Quantum Information Science 2009 (AQIS2009), Nanjing, China, Proceedings of AQIS2009, pp.203-204, (2009.8).

(2010)
    1. T. S. Usuda and K. Shiromoto,
      Analytical expression of s-th power of Gram matrix for group covariant signals and its application,
      The Tenth International Conference on Quantum Communication, Measurement and Computation (QCMC2010), Abstracts of Papers of QCMC2010, p.256, P3-27, (2010.7).
      in Quantum Communication, Measurement and Computing (QCMC), AIP Conference Proceedings Vol.1363, T. Ralph and P.K. Lam (Eds.), American Institute of Physics, New York, pp.97-100, (2011). doi: 10.1063/1.3630156

    2. M. Ota, H. Kumazawa, K. Shiromoto, and T. S. Usuda,
      Formula of channel matrix for coded quantum signals by classical linear codes over Zm,
      2010 International Symposium on Information Theory and Its Applications (ISITA2010), Taichung, Taiwan, Proceedings of ISITA2010, pp.1035-1040, (2010.10). doi: 10.1109/ISITA.2010.5649495

    3. Y. Takamura, S. Usami, and T. S. Usuda,
      On attainment of the capacity of broadband quantum channel by wavelength division multiplexing,
      2010 International Symposium on Information Theory and Its Applications (ISITA2010), Taichung, Taiwan, Proceedings of ISITA2010, pp.1045-1049, (2010.10). doi: 10.1109/ISITA.2010.5649485

(2011)
    1. M. Takeshita, M. Ota, and T. S. Usuda,
      The semi-classical quantum receiver for coherent-state signals and its property,
      11th Asian Quantum Information Science Conference (AQIS2011), Busan, Korea, Proceedings of AQIS2011, pp.137-138, (2011.8).

    2. S. Nagahashi, T. S. Usuda, and I. Takumi,
      Property of 2-EPP using QECC and binary search consisting of various codes,
      11th Asian Quantum Information Science Conference (AQIS2011), Busan, Korea, Proceedings of AQIS2011, pp.153-154, (2011.8).

    3. M. Ota, K. Shiromoto, and T. S. Usuda,
      Application of formula of channel matrix for quantum signals coded by linear codes over the ring of integers,
      11th Asian Quantum Information Science Conference (AQIS2011), Busan, Korea, Proceedings of AQIS2011, pp.155-156, (2011.8).

    4. Y. Yazaki, S. Usami, and T. S. Usuda,
      Two-way entanglement purification protocol using QECCs and binary search for various quantum channels,
      11th Asian Quantum Information Science Conference (AQIS2011), Busan, Korea, Proceedings of AQIS2011, pp.157-158, (2011.8).

    5. H. Takeuchi and T. S. Usuda,
      Properties of entanglement-assisted classical capacity using a quasi-Bell state,
      11th Asian Quantum Information Science Conference (AQIS2011), Busan, Korea, Proceedings of AQIS2011, pp.177-178, (2011.8).

(2012)
    1. K. Nakahira and T. S. Usuda,
      A generalized Dolinar receiver with inconclusive results,
      11th International Conference on Quantum Communication, Measurement and Computing (QCMC2012), Vienna, Austria, Abstracts of Papers of QCMC2012, p.229, P2-22, (2012.7).
      in Eleventh International Conference on Quantum Communication, Measurement and Computation (QCMC), AIP Conference Proceedings, Vol.1633, H.-J. Schmiedmayer and P. Walther (Eds.), American Institute of Physics, New York, pp.74-76, (2014). doi: 10.1063/1.4903099

    2. T. S. Usuda, Y. Ishikawa, and K. Shiromoto,
      A class of group covariant signal sets and its necessary and sufficient condition,
      11th International Conference on Quantum Communication, Measurement and Computing (QCMC2012), Vienna, Austria, Abstracts of Papers of QCMC2012, p.361, P3-57, (2012.8).
      in Eleventh International Conference on Quantum Communication, Measurement and Computation (QCMC), AIP Conference Proceedings, Vol.1633, H.-J. Schmiedmayer and P. Walther (Eds.), American Institute of Physics, New York, pp.201-203, (2014). doi: 10.1063/1.4903137

    3. S. Nagahashi, T. S. Usuda, and I. Takumi,
      Improvement of 2-EPP using quantum error correcting codes and binary search
      2012 International Symposium on Information Theory and Its Applications (ISITA2012), Honolulu, Hawaii, Proceedings of ISITA2012, pp.202-205, (2012.10).

    4. Y. Yazaki, S. Usami, and T. S. Usuda,
      Superiority of 2-EPPs to 1-EPPs with finite entangled resources
      2012 International Symposium on Information Theory and Its Applications (ISITA2012), Honolulu, Hawaii, Proceedings of ISITA2012, pp.206-210, (2012.10).

    5. K. Ohashi and T. S. Usuda,
      Property of capacity by WDM for attenuated quantum channel
      2012 International Symposium on Information Theory and Its Applications (ISITA2012), Honolulu, Hawaii, Proceedings of ISITA2012, pp.215-218, (2012.10).

    6. H. Yamashita, T. S. Usuda, and S. Usami,
      Error performance of semi-classical quantum receivers for CPPM signals in KCQ key generation,
      2012 International Symposium on Information Theory and Its Applications (ISITA2012), Honolulu, Hawaii, Proceedings of ISITA2012, pp.311-314, (2012.10).

    7. H. Takeuchi, S. Yamaguchi, and T. S. Usuda,
      Entanglement-assisted classical communication using quasi Bell states,
      The 1st International Workshop on Entangled Coherent State and Its Application to Quantum Information Science -Towards Macroscopic Quantum Communications-, Tokyo, (2012.11).
      Proceedings of the First International Workshop on ECS and Its Application to QIS; T.M.Q.C., T.S. Usuda and K. Kato (Eds.), Tamagawa University Quantum ICT Research Institute, pp.115-119, (2013).

(2013)
    1. T. Segawa, T. S. Usuda, and S. Usami,
      Is 2-EPP good at low rates for a phase damping channel?,
      13th Asian Quantum Information Science Conference (AQIS2013), Chennai, India, Extended Abstracts of AQIS2013, pp.133-134, (2013.8).

    2. T. Kondo and T. S. Usuda,
      Improvement of quasi-optimum quantum receiver for M-ary PSK coherent-state signals,
      13th Asian Quantum Information Science Conference (AQIS2013), Chennai, India, Extended Abstracts of AQIS2013, pp.189-190, (2013.8).

    3. D. Sasaki and T. S. Usuda,
      Constructing method of 2-EPP with different quantum error correcting codes,
      13th Asian Quantum Information Science Conference (AQIS2013), Chennai, India, Extended Abstracts of AQIS2013, pp.191-192, (2013.8).

    4. Y. Ishikawa, K. Shiromoto, and T. S. Usuda,
      Formula for the channel matrix of a certain class of (G,χ)-covariant signals,
      13th Asian Quantum Information Science Conference (AQIS2013), Chennai, India, Extended Abstracts of AQIS2013, pp.209-210, (2013.8).

    5. S. Yamaguchi and T. S. Usuda,
      Maximization of Holevo information for entanglement-assisted classical communication using quasi-Bell states,
      13th Asian Quantum Information Science Conference (AQIS2013), Chennai, India, Extended Abstracts of AQIS2013, pp.213-214, (2013.8).

(2014)
    1. S. Asano, K. Nakahira, and T. S. Usuda
      Approximation of minimum error probability in distinguishing M-ary quantum signals using the trace distance between two neighboring signals,
      14th Asian Quantum Information Science Conference (AQIS2014), Kyoto, Japan, Proceedings of AQIS2014, pp.171-172, (2014.8).

    2. S. Koyama, K. Nakahira, and T. S. Usuda
      Error performance of modifed Kennedy receiver in the presence of phase noise,
      14th Asian Quantum Information Science Conference (AQIS2014), Kyoto, Japan, Proceedings of AQIS2014, pp.185-186, (2014.8).

    3. K. Sato, K. Nakahira, S. Usami, and T. S. Usuda
      Error performance for non-destructive quantum receiver of M-ary coherent-state signals,
      2014 International Symposium on Information Theory and Its Applications (ISITA2014), Melbourne, Australia, Proceedings of ISITA2014, pp.246-249, (2014.10).

    4. N. Iwata and T. S. Usuda,
      Quantum gain of coding by polar codes with finite codeword length,
      2014 International Symposium on Information Theory and Its Applications (ISITA2014), Melbourne, Australia, Proceedings of ISITA2014, pp.250-253, (2014.10).

    5. S. Asano and T. S. Usuda,
      A simple approximation of minimum error probability using trace distance,
      2014 International Symposium on Information Theory and Its Applications (ISITA2014), Melbourne, Australia, Proceedings of ISITA2014, pp.254-258, (2014.10).

    6. S. Koyama and T. S. Usuda,
      Error performance of optimum quantum detection for BPSK signals in the presence of phase noise and its robustness,
      2014 International Symposium on Information Theory and Its Applications (ISITA2014), Melbourne, Australia, Proceedings of ISITA2014, pp.259-263, (2014.10).

    7. Y. Umemura, T. S. Usuda, and S. Usami,
      Advantage creation property of QAM-type KCQ key generation,
      2014 International Symposium on Information Theory and Its Applications (ISITA2014), Melbourne, Australia, Proceedings of ISITA2014, p.346, (2014.10).

    8. M. Tanaka, T. Sogabe, K. Shiromoto, and T. S. Usuda,
      Group covariance and formula of channel matrix of coded 4PSK signals by linear codes over F4,
      2014 International Symposium on Information Theory and Its Applications (ISITA2014), Melbourne, Australia, Proceedings of ISITA2014, p.348, (2014.10).

    9. T. S. Usuda, T. Sogabe, and K. Shiromoto,
      Formula of channel matrix for covariant signal set with respect to a direct product of groups,
      12th International Conference on Quantum Communication, Measurement and Computing (QCMC2014), Hefei, China, Abstracts of Papers of QCMC2014, p.45, B12, (2014.11).

(2015)
    1. S. Mizuno, Y. Moriizumi, T. S. Usuda, and T. Sogabe,
      On an initial guess of Newton's method for the matrix square root based on a sphere constrained optimization problem,
      International Workshop on Information Technology, Applied Mathematics and Science, Kyoto, Japan, (2015.3).

    2. M. Tanaka, A. Ohashi, T. Sogabe, and T. S. Usuda,
      Derivation of analytical expression of channel matrix for coded 4PSK signals using tensor product decomposition of Gram matrix,
      15th Asian Quantum Information Science Conference (AQIS2015), Seoul, Korea, Proceedings of AQIS2015, pp.143-144, (2015.8).

    3. S. Takahira, A. Ohashi, T. Sogabe, and T. S. Usuda,
      Quantum-classical hybrid algorithm to solve linear equations for k-tridiagonal matrix,
      15th Asian Quantum Information Science Conference (AQIS2015), Seoul, Korea, Proceedings of AQIS2015, pp.154-155, (2015.8).

    4. A. Kadoya, Y. Umemura, S. Asano, N. Iwata, and T. S. Usuda,
      KCQ using binary linear code and its performance,
      15th Asian Quantum Information Science Conference (AQIS2015), Seoul, Korea, Proceedings of AQIS2015, pp.161-162, (2015.8).

    5. S. Asano and T. S. Usuda,
      On accuracy of approximation of optimum quantum receiver performance using trace distance,
      15th Asian Quantum Information Science Conference (AQIS2015), Seoul, Korea, Proceedings of AQIS2015, pp.181-182, (2015.8).

(2016)
    1. T. S. Usuda and S. Asano,
      Simple approximation of minimum error probability for pure-state signals,
      13th International Conference on Quantum Communication, Measurement and Computing (QCMC2016), Singapore, Abstracts of Papers of QCMC2016, p.114, P2-277, (2016.7).

    2. K. Kita, S. Koyama, M. Tanaka, and T. S. Usuda,
      Attenuated quantum channel with probabilistic transmissivity,
      16th Asian Quantum Information Science Conference (AQIS2016), Taipei, Taiwan, Extended Abstracts of AQIS2016, pp.63-64, (2016.8).

    3. M. Tanaka, A. Ohashi, and T. S. Usuda,
      Group covariance of q-ary PSK coherent-state signals coded by codes over extension field Fq,
      16th Asian Quantum Information Science Conference (AQIS2016), Taipei, Taiwan, Extended Abstracts of AQIS2016, pp.73-74, (2016.8).

    4. S. Takahira, A. Ohashi, T. Sogabe, and T. S. Usuda,
      Quantum algorithm for linear equations with a circulant matrix,
      16th Asian Quantum Information Science Conference (AQIS2016), Taipei, Taiwan, Extended Abstracts of AQIS2016, pp.87-88, (2016.8).

    5. Y. Nishino, S. Takahira, A. Kadoya, A. Ohashi, and T. S. Usuda,
      Reduction of computation complexity of classical optimal decoding by adiabatic quantum computation,
      16th Asian Quantum Information Science Conference (AQIS2016), Taipei, Taiwan, Extended Abstracts of AQIS2016, pp.102-103, (2016.8).

    6. Y. Nishino, S. Takahira, A. Kadoya, and T. S. Usuda,
      Application of adiabatic quantum computation to classical optimal decoding,
      2016 International Symposium on Information Theory and Its Applications (ISITA2016), Monterey, California, USA, Proceedings of ISITA2016, p.563, (2016.10-11).

    7. M. Tanaka, A. Ohashi, and T. S. Usuda,
      4PSK coherent-state signals can be narrow sense group covariant with respect to F4 by coding,
      2016 International Symposium on Information Theory and Its Applications (ISITA2016), Monterey, California, USA, Proceedings of ISITA2016, pp.692-696, (2016.10-11).

(2017)
    1. Y. Nishino, S. Takahira, and T. S. Usuda,
      Annealing schedule for classical optimal decoding using adiabatic quantum computation,
      17th Asian Quantum Information Science Conference (AQIS2017), Singapore, Proceedings of AQIS2017, pp.202-204, (2017.9).

    2. T. Wang, K. Kita, and T. S. Usuda,
      Channel capacity of quantum channel with beam wandering,
      17th Asian Quantum Information Science Conference (AQIS2017), Singapore, Proceedings of AQIS2017, pp.215-217, (2017.9).

    3. N. Matsumoto, A. Kadoya, S. Takahira, Y. Nishino, and T. S. Usuda,
      Origin of the gap between the minimum error probability and its simple approximation,
      17th Asian Quantum Information Science Conference (AQIS2017), Singapore, Proceedings of AQIS2017, pp.264-266, (2017.9).

    4. S. Takahira, A. Ohashi, T. Sogabe, and T. S. Usuda,
      Amplitude estimation based algorithm for circulant linear systems,
      17th Asian Quantum Information Science Conference (AQIS2017), Singapore, Proceedings of AQIS2017, pp.279-281, (2017.9).

(2018)
    1. K. Nakahira, K. Kato, and T. S. Usuda,
      Optimal unambiguous state discrimination with sequential measurement,
      14th International Conference on Quantum Communication, Measurement and Computing (QCMC2018), Baton Rouge, LA, USA, P72, (2018.3).

    2. K. Sato, S. Takahira, and T. S. Usuda,
      SIC ensemble is ``Scrooge" with second-order mutual Renyi information criterion,
      14th International Conference on Quantum Communication, Measurement and Computing (QCMC2018), Baton Rouge, LA, USA, P80, (2018.3).

    3. S. Takahira, A. Ohashi, T. Sogabe, and T. S. Usuda,
      Quantum algorithm for matrix functions by Cauchy's integral formula,
      18th Asian Quantum Information Science Conference (AQIS2018), Nagoya, Extended Abstracts of AQIS2018, 213, (2018.9).

    4. K. Sato, S. Takahira, K. Nakahira, and T. S. Usuda,
      Maximizing α-order Mutual Renyi Information for group covariant SIC Ensemble,
      18th Asian Quantum Information Science Conference (AQIS2018), Nagoya, Extended Abstracts of AQIS2018, 72, (2018.9).

    5. K. Ishikawa, T. Wang, and T. S. Usuda,
      Effect of incomplete phase shift on quantum reading using a quasi-Bell state in non-symmetric loss model,
      18th Asian Quantum Information Science Conference (AQIS2018), Nagoya, Extended Abstracts of AQIS2018, 76, (2018.9).

    6. T. Wang, K. Nakahira, and T. S. Usuda,
      Error performance of optimum quantum measurement in the presence of non-Gaussian noise and Gaussian noise,
      18th Asian Quantum Information Science Conference (AQIS2018), Nagoya, Extended Abstracts of AQIS2018, 108, (2018.9).

    7. N. Matsumoto, S. Takahira, and T. S. Usuda,
      Relation between quantumness and the approximation accuracy of the minimum error probability,
      18th Asian Quantum Information Science Conference (AQIS2018), Nagoya, Extended Abstracts of AQIS2018, 202, (2018.9).

    8. T. Wang, K. Nakahira, and T. S. Usuda,
      Error performance and robustness of optimum quantum detection for MPSK signals in the presence of phase noise,
      2018 International Symposium on Information Theory and Its Applications (ISITA2018), Singapore, Proceedings of ISITA2018, pp.344-348, (2018.10).

    9. K. Ishikawa, T. Wang, and T. S. Usuda,
      Effect of non-symmetric loss on quantum reading using a quasi-Bell state,
      2018 International Symposium on Information Theory and Its Applications (ISITA2018), Singapore, Proceedings of ISITA2018, pp.467-471, (2018.10).

    10. S. Takahira and T. S. Usuda,
      Applying a symmetrization method by coding to non-symmetric mixed-state signals,
      2018 International Symposium on Information Theory and Its Applications (ISITA2018), Singapore, Proceedings of ISITA2018, pp.472-475, (2018.10).

(2019年)
    1. K. Ishikawa, T. Wang, and T. S. Usuda,
      Comparison of quantum reading in non-symmetric loss using maximum and non-maximum quasi-Bell states,
      19th Asian Quantum Information Science Conference (AQIS2019), Seoul, Korea, Proceedings of AQIS2019, Poster Day 1, pp.111-113, (2019.8).

    2. Y. Takahashi, K. Ishikawa, S. Usami, and T. S. Usuda,
      Performance Evaluation of ghost imaging with orthogonal/non-orthogonal quantum states,
      19th Asian Quantum Information Science Conference (AQIS2019), Seoul, Korea, Proceedings of AQIS2019, Poster Day 1, pp.117-120, (2019.8).

    3. K. Sato, S. Takahira, K. Nakahira, and T. S. Usuda,
      Relation of `α-order Renyi' subentropy and mutual information,
      19th Asian Quantum Information Science Conference (AQIS2019), Seoul, Korea, Proceedings of AQIS2019, Poster Day 1, pp.124-126, (2019.8).

    4. T. Wang, K. Nakahira, and T. S. Usuda,
      Design criteria for a robust quantum receiver in the presence of phase noise,
      19th Asian Quantum Information Science Conference (AQIS2019), Seoul, Korea, Proceedings of AQIS2019, Poster Day 1, pp.142-145, (2019.8).

    5. M. Yoshida, S. Usami, and T. S. Usuda,
      Evaluation of quantum gain for KCQ protocol using best binary codes in high or low rate,
      19th Asian Quantum Information Science Conference (AQIS2019), Seoul, Korea, Proceedings of AQIS2019, Poster Day 1, pp.146-149, (2019.8).

(2020年)
    1. T. Wang and T. S. Usuda,
      Effect of non-Gaussian noise due to beam wandering on error performance of quantum measurement,
      2020 International Symposium on Information Theory and Its Applications (ISITA2020), Kapolei, Hawai'i, Proceedings of ISITA2020, pp.106-110, (2020.10).

    2. Y. Takahashi, T. Wang, S. Usami, and T. S. Usuda,
      Performance evaluation of ghost imaging with orthogonal/non-orthogonal quantum states in terms of image quality,
      2020 International Symposium on Information Theory and Its Applications (ISITA2020), Kapolei, Hawai'i, Proceedings of ISITA2020, pp.111-115, (2020.10).

    3. J. Yamauchi, Y. Takahashi, T. Wang, and T. S. Usuda,
      Quantum illumination using quasi-Bell states,
      2020 International Symposium on Information Theory and Its Applications (ISITA2020), Kapolei, Hawai'i, Proceedings of ISITA2020, pp.116-120, (2020.10).

    4. R. Miyazaki, M. Yoshida, T. Wang, and T. S. Usuda,
      Simplification of the calculation of the channel matrix for AMPM coherent-state signals,
      2020 International Symposium on Information Theory and Its Applications (ISITA2020), Kapolei, Hawai'i, Proceedings of ISITA2020, pp.121-125, (2020.10).

    5. M. Yoshida, S. Usami, and T. S. Usuda,
      Evaluation of quantum gain for KCQ protocol using best multi-ary codes in high or low rate,
      20th Asian Quantum Information Science Conference (AQIS2020), Sydney, Australia, Proceedings of AQIS2020, p.49 (2 pages), (2020.12).

    6. R. Miyazaki, M. Yoshida, T. Wang, S. Takahira, and T. S. Usuda,
      Simplification of the calculation of the channel matrix for 4m2-ary QAM coherent-state signals,
      20th Asian Quantum Information Science Conference (AQIS2020), Sydney, Australia, Proceedings of AQIS2020, p.89 (2 pages), (2020.12).

    7. R. Nakagawa, T. Wang, and T. S. Usuda,
      Kraus representation of probabilistic attenuated channel,
      20th Asian Quantum Information Science Conference (AQIS2020), Sydney, Australia, Proceedings of AQIS2020, p.91 (2 pages), (2020.12).

    8. T. Wang and T. S. Usuda,
      Exact solution of error probability for quantum illumination with attenuation using quasi-Bell state,
      20th Asian Quantum Information Science Conference (AQIS2020), Sydney, Australia, Proceedings of AQIS2020, p.135 (2 pages), (2020.12).

    9. J. Yamauchi, Y. Takahashi, T. Wang, and T. S. Usuda,
      Quantum illumination by quasi-Bell states with thermal noise,
      20th Asian Quantum Information Science Conference (AQIS2020), Sydney, Australia, Proceedings of AQIS2020, p.138 (2 pages), (2020.12).

    10. Y. Takahashi, T. Wang, S. Usami, and T. S. Usuda,
      PSNR characteristics of quantum ghost imaging with multiple positions illumination,
      20th Asian Quantum Information Science Conference (AQIS2020), Sydney, Australia, Proceedings of AQIS2020, p.216 (2 pages), (2020.12).

(2021年)
    1. S. Isokawa, R. Nakagawa, T. Wang, and T. S. Usuda,
      Geometric representation of the Belavkin weighted square-root measurement for two-dimensional signals,
      21st Asian Quantum Information Science Conference (AQIS2021), Tokyo, Japan, Abstracts of AQIS2021, PA5, (2021.9).

    2. R. Miyazaki, T. Wang, S. Takahira, and T. S. Usuda,
      Simplication of the calculation of the channel matrix for nm-ary AMPM coherent-state signals,
      21st Asian Quantum Information Science Conference (AQIS2021), Tokyo, Japan, Abstracts of AQIS2021, PB5, (2021.9).

    3. S. Takahira, A. Ohashi, T. Sogabe, and T. S. Usuda,
      Quantum algorithms based on the block-encoding framework for matrix functions by contour integrals,
      21st Asian Quantum Information Science Conference (AQIS2021), Tokyo, Japan, Abstracts of AQIS2021, PB6, (2021.9).

    4. T. Wang, S. Takahira, and T. S. Usuda,
      Error performance of ASK-type asymmetric quantum communication,
      21st Asian Quantum Information Science Conference (AQIS2021), Tokyo, Japan, Abstracts of AQIS2021, PC5, (2021.9).

    5. Y. Adachi, S. Usami, and T. S. Usuda,
      Equivalence of quantum codes in quantum deletion insertion channel with erasure errors,
      21st Asian Quantum Information Science Conference (AQIS2021), Tokyo, Japan, Abstracts of AQIS2021, PC20, (2021.9).

    6. J. Yamauchi, T. Wang, and T. S. Usuda,
      Quantum illumination by quasi-Bell state is always superior to laser radar,
      21st Asian Quantum Information Science Conference (AQIS2021), Tokyo, Japan, Abstracts of AQIS2021, PD11, (2021.9).

    7. R. Nakagawa, T. Wang, and T. S. Usuda,
      Equations of conditions for Kraus operators of probabilistic attenuated channel,
      21st Asian Quantum Information Science Conference (AQIS2021), Tokyo, Japan, Abstracts of AQIS2021, PD17, (2021.9).

(2022年)
    1. S. Isokawa, K. Miyachi, T. Wang, S. Takahira, and T. S. Usuda,
      Geometric representation and optimum weights of the BWSRM for binary mixed state signals,
      2022 International Symposium on Information Theory and Its Applications (ISITA2022), Tsukuba, Japan, Proceedings of ISITA2022, p.218, (2022.10.19).

    2. Y. Adachi, S. Usami, and T. S. Usuda,
      Towards the construction of quantum error correcting codes for multiple insertion errors,
      2022 International Symposium on Information Theory and Its Applications (ISITA2022), Tsukuba, Japan, Proceedings of ISITA2022, p.219, (2022.10.19).

    3. Y. Wakahara, S. Takahira, S. Usami, and T. S. Usuda,
      Effects of coding for CPPM-type quantum cipher,
      2022 International Symposium on Information Theory and Its Applications (ISITA2022), Tsukuba, Japan, Proceedings of ISITA2022, p.220, (2022.10.19).

    4. S. Sameshima, T. Wang, S. Usami, and T. S. Usuda,
      PSK-type asymmetric quantum communication and its attenuation characteristics,
      2022 International Symposium on Information Theory and Its Applications (ISITA2022), Tsukuba, Japan, Proceedings of ISITA2022, pp.241-245, (2022.10.19).

    5. S. Isokawa, K. Miyachi, T. Wang, S. Takahira, and T. S. Usuda,
      Geometric representation and optimum weight of the BWSRM for mixed state signals,
      22nd Asian Quantum Information Science Conference (AQIS2022), University of Science and Technology of China, China (online), Poster Number 19, (2022.12.17).

    6. Y. Adachi, S. Usami, and T. S. Usuda,
      On the construction of quantum error correcting codes for 1-deletion and 1-insertion errors,
      22nd Asian Quantum Information Science Conference (AQIS2022), University of Science and Technology of China, China (online), Poster Number 20, (2022.12.17).

    7. Y. Wakahara, S. Takahira, S. Usami, and T. S. Usuda,
      Applying outer codes to CPPM-type quantum cipher,
      22nd Asian Quantum Information Science Conference (AQIS2022), University of Science and Technology of China, China (online), Poster Number 33, (2022.12.18).

    8. S. Sameshima, T. Wang, S. Usami, and T. S. Usuda,
      PSK-type asymmetric quantum communication and its noisy environment characteristics,
      22nd Asian Quantum Information Science Conference (AQIS2022), University of Science and Technology of China, China (online), Poster Number 37, (2022.12.18).

(2023年)
    1. S. Takahira, A. Ohashi, T. Sogabe, and T. S. Usuda,
      On the performance for the block-encoding of the matrix functions evaluated by the numerical quadrature method,
      23rd Asian Quantum Information Science Conference (AQIS2023), KIAS (Korea Institute for Advanced Study), Seoul, Korea, Abstracts of AQIS2023 Poster I, p.177-180, (2023.8.28).

    2. T. Wang and T. S. Usuda,
      Quantum Chernoff Bound for Quantum Reading Using the Quasi-Bell State,
      23rd Asian Quantum Information Science Conference (AQIS2023), KIAS (Korea Institute for Advanced Study), Seoul, Korea, Abstracts of AQIS2023 Poster I, p.297-300, (2023.8.28).

    3. S. Sameshima, T. Wang, S. Takahira, S. Usami, and T. S. Usuda,
      On the optimal quantum state of BPSK-type asymmetric quantum communication in an attenuation environment,
      23rd Asian Quantum Information Science Conference (AQIS2023), KIAS (Korea Institute for Advanced Study), Seoul, Korea, Abstracts of AQIS2023 Poster II, p.44-47, (2023.8.29).

    4. K. Masaki, T. Wang, S. Takahira, S. Usami, and T. S. Usuda,
      Comparison of several quantum receivers for coherent-state signals by using classical reliability function,
      23rd Asian Quantum Information Science Conference (AQIS2023), KIAS (Korea Institute for Advanced Study), Seoul, Korea, Abstracts of AQIS2023 Poster II, p.114-117, (2023.8.29).

    5. S. Kitamura, T. Wang, S. Takahira, and T. S. Usuda,
      Calculation of capacity with discrete-valued inputs using efficiently obtained eigenvalues,
      23rd Asian Quantum Information Science Conference (AQIS2023), KIAS (Korea Institute for Advanced Study), Seoul, Korea, Abstracts of AQIS2023 Poster II, p.267-270, (2023.8.29).

    6. Y. Wakahara, S. Takahira, S. Usami, and T. S. Usuda,
      Comparison of capacity and coding rates in CPPM-type quantum cipher with outer codes,
      23rd Asian Quantum Information Science Conference (AQIS2023), KIAS (Korea Institute for Advanced Study), Seoul, Korea, Abstracts of AQIS2023 Poster II, p.279-281, (2023.8.29).

    7. Y. Horiba, T. Wang, and T. S. Usuda,
      Effect of scattering on quantum ghost imaging and ordinary imaging,
      23rd Asian Quantum Information Science Conference (AQIS2023), KIAS (Korea Institute for Advanced Study), Seoul, Korea, Abstracts of AQIS2023 Poster III, p.261-264, (2023.8.31).


Other presentations


  1. T. S. Usuda,
    Y-00 key generation with non-weak coherent-states
    Symposium on quantum cryptography by optical communications, Chuo University, Tokyo, Japan, (2005.11).

  2. T. S. Usuda,
    Modulation, coding and decoding in classical-quantum channel
    Osamu Hirota, A True Quantum Communications Channel, Perimeter Institute for Theoretical Physics, Waterloo, Canada, (2008.6).


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Last modified: April 11 2024