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Probing topological defect formation in a quantum annealer

ORAL

Abstract

When a quantum phase transition is crossed in finite time, the breakdown of adiabatic dynamics leads to the formation of topological defects. The average density of defects scales with the quench rate following a universal power-law predicted by the Kibble- Zurek mechanism. The later provides useful heuristics for adiabatic quantum computation. Physics beyond the Kibble-Zurek mechanism can be probed by characterizing the full counting statistics of topological defects. We argue that the distribution of the number of defects generally follows a Poisson binomial distribution with all cumulants exhibiting a universal power-law scaling with the quench rate. As an example, we report the exact kink number distribution in the transverse-field quantum Ising model. For this system, we test kink statistics in a D-Wave machine and show that the study of the kink number distribution can be used to benchmark the performance of a quantum processor.

References:
[1] A. del Campo, Phys. Rev. Lett. 121, 200601 (2018)
[2] Jin-Ming Cui, F. J. Gómez-Ruiz, Yun-Feng Huang, Chuan-Feng Li, Guang-Can Guo, A. del Campo, arXiv:1903.02145
[3] Y. Bando et al, TBS (2019)

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Presenters

  • Adolfo Del Campo

    Physics, Donostia International Physics Center, 2. Donostia International Physics Center, E-20018 San Sebastián, Spain, Donostia International Physics Center (DIPC), University of Massachusetts Boston

Authors

  • Yuki Bando

    Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan

  • Fernando J. Gómez-Ruiz

    2. Donostia International Physics Center, E-20018 San Sebastián, Spain

  • Masayuki Ohzeki

    3. Tohoku University, Sendai 980-8579, Japan

  • Hiroki Oshiyama

    3. Tohoku University, Sendai 980-8579, Japan

  • Naokazu Shibata

    3. Tohoku University, Sendai 980-8579, Japan

  • Yuki Susa

    Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan

  • Sei Suzuki

    4. Saitama Medical University, Moroyama, Saitama 350-0495, Japan

  • Daniel A Lidar

    University of Southern California, Univ of Southern California, 5. University of Southern California, Los Angeles, California 90089, USA

  • Adolfo Del Campo

    Physics, Donostia International Physics Center, 2. Donostia International Physics Center, E-20018 San Sebastián, Spain, Donostia International Physics Center (DIPC), University of Massachusetts Boston

  • Hidetoshi Nishimori

    Tokyo Institute of Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan