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Wednesday, May 9, 2018 - 11:15 to 12:30 Auditorium

In this talk, we will present the basic concept, operational principle and experimental perfor-mance of a novel computing machine based on the network of degenerate optical parametric oscillators. The developed machine has 2048 qubits with all-to-all connections and is now available as a cloud system via internet. There are at least three quantum computing models proposed today: they are unitary quan-tum computation, adiabatic quantum computation and dissipative quantum computation. A gate model quantum computer implements the unitary quantum computation model and is expected to solve particular problems with hidden periodicity or specific structure [1,2], while a coherent Ising machine (CIM), implements the dissipative quantum computation model [3,4] and is expected to solve unstructured combinatorial optimization problems. We will dis-cuss the two types of CIMs, optical delay line coupling machine [5] and measurement feed-back coupling machine [6], as well as the performance comparison against modern digital computers and algorithms [7]. References [1] D. Deutsch, Proc. of the Royal Society of London. Series A, Mathematical and Physical Sciences, 400, 97–117 (1985); D. Deutsch and R. Jozsa, Proc. Roy. Soc. (London) A 439, 553-558 (1992). [2] P. W. Shor, Proc. of the 35th Annual Symposium on Foundations of Computer Science, IEEE Computer Socie-ty Press,124-134 (1994). [3] W. H. Zurek, Rev. Mod. Phys. 75, 715-775 (2003). [4] F. Verstraete, M. M. Wolf, and J. I. Cirac, Nature Phys. 5, 633-636 (2009). [5] A. Marandi Z. Wang, K. Takata, R. L. Byer, and Y. Yamamoto, Nature Photonics 8, 937-942 (2014); T. Inagaki, K. Inaba, R. Hamerly, K. Inoue, Y. Yamamoto, and H. Takesue, Nature Photonics 10, 415-419 (2016). [6] T. Inagaki, Y. Haribara, K. Igarashi, T. Sonobe, S. Tamate, T. Honjo, A. Marandi, P. L. McMahon, T. Umeki, K. Enbutsu, O. Tadanaga, H. Takenouchi, K. Aihara, K. Kawarabayashi, K. Inoue, S. Utsunomiya, and H. Takesue, Science 354, 603-606 (2016); P. L. McMahon, A. Marandi, Y. Haribara, R. Hamerly, C. Langrock, S. Tamate, T. Inagaki, H. Takesue, S. Utsunomiya, K. Aihara, R. L. Byer, M. M. Fejer, H. Mabuchi, and Y. Yamamoto, Science 354, 614-617 (2016). [7] Y. Haribara, H. Ishikawa, S. Utsunomiya, K. Aihara, and Y. Yamamoto, Quantum Sci. Tech. 2, 044002 (2017).