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Unitary equivalence classes of split-step quantum walks

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Abstract

In this study, we investigate the unitary equivalence of split-step quantum walks (SSQWs). Introduced by Kitagawa and generalized by Suzuki, SSQWs are two-state discrete-time quantum walks on a one-dimensional lattice. In this work, we define a new class of quantum walks that includes all SSQWs by making use of the rank conditions, which state that (1) the rank of operators representing the walk from vertex x to vertex \(x\pm 1\) is less than or equal to 1 and that (2) the rank from vertex x to x (i.e., to itself) is less than or equal to 2. Initially, we abstractly define quantum walks in this class, then clarify by presenting the explicit form of such quantum walks. We also calculate their unitary equivalence classes and show that four real parameters are required for each vertex to parameterize the unitary equivalence classes. Further, we consider the unitary equivalence of Suzuki’s SSQWs and prove that all parameters of Suzuki’s SSQWs can be real. Finally, we discuss the chiral symmetry of SSQWs.

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References

  1. Abdel-Aty, A.-H., Kadry, H., Zidan, M., et al.: A quantum classification algorithm for classification incomplete patterns based on entanglement measure. J. Intell. Fuzzy Syst. 38, 2809–2816 (2020)

    Article  Google Scholar 

  2. Cedzich, C., Geib, T., Grünbaum, F.A., Stahl, C., Velazquez, L., Werner, A.H., Werner, R.F.: The Topological Classification of One-Dimensional Symmetric Quantum Walks. Ann. Henri Poincaré 19, 325–383 (2018)

    Article  MathSciNet  ADS  Google Scholar 

  3. Fuda, T., Funakawa, D., Suzuki, A.: Localization of a multi-dimensional quantum walk with one defect. Quantum Inf. Process. 16, 203 (2017)

    Article  MathSciNet  ADS  Google Scholar 

  4. Fuda, T., Funakawa, D., Suzuki, A.: Localization for a one-dimensional split-step quantum walk with bound states robust against perturbations. J. Math. Phys. 59, 082201 (2018)

    Article  MathSciNet  ADS  Google Scholar 

  5. Fuda, T., Funakawa, D., Suzuki, A.: Weak limit theorem for a one-dimensional split-step quantum walk. Rev. Roumaine Math. Pures Appl. 64, 157–165 (2019)

    MathSciNet  MATH  Google Scholar 

  6. Goyal, S.K., Konrad, T., Diósi, L.: Unitary equivalence of quantum walks. Phys. Lett. A 379, 100–104 (2015)

    Article  MathSciNet  ADS  Google Scholar 

  7. Konno, N., Ide, Y.: New Developments of Quantum Walks (In Japanese). Baifukan, Tokyo (2019)

  8. Kitagawa, T.: Topological phenomena in quantum walks: elementary introduction to the physics of topological phases. Quantum Inf. Process. 11, 1107–1148 (2012)

    Article  MathSciNet  Google Scholar 

  9. Kitagawa, T., Rudner, M.S., Berg, E., Demler, E.: Exploring topological phases with quantum walks. Phys. Rev. A 82, 033429 (2010)

    Article  ADS  Google Scholar 

  10. Liu, W., Wu, Q., Shen, J., et al.: An optimized quantum minimum searching algorithm with sure-success probability and its experiment simulation with Cirq. J. Ambient Intell. Hum. Comput. (2021)

  11. Kuriki, S., Nirjohor, M.S.A., Ohno, H.: Parameterization of quantum walks on cycles. Quantum Inf. Process. 20, 28 (2021)

    Article  MathSciNet  ADS  Google Scholar 

  12. Matsuzawa, Y.: An index theorem for split-step quantum walks. Quantum Inf. Process. 19, 227 (2020)

    Article  MathSciNet  ADS  Google Scholar 

  13. Ohno, H.: Unitary equivalent classes of one-dimensional quantum walks. Quantum Inf. Process. 15, 3599–3617 (2016)

    Article  MathSciNet  ADS  Google Scholar 

  14. Ohno, H.: Unitary equivalence classes of one-dimensional quantum walks II. Quantum Inf. Process. 16, 287 (2017)

    Article  MathSciNet  ADS  Google Scholar 

  15. Ohno, H.: Parameterization of translation-invariant two-dimensional two-state quantum walks. Acta Math. Vietnam. 43, 737–747 (2018)

    Article  MathSciNet  Google Scholar 

  16. Portugal, R.: Quantum Walks and Search Algorithms. Springer (2018)

  17. Sagheer, A., Zidan, M., Abdelsamea, M.M.: A novel autonomous perceptron model for pattern classification applications. Entropy 21, 763 (2019)

    Article  MathSciNet  ADS  Google Scholar 

  18. Segawa, E., Suzuki, A.: Generator of an abstract quantum walk. Quantum Stud. Math. Found. 3, 11–30 (2016)

    Article  MathSciNet  Google Scholar 

  19. Suzuki, A.: Supersymmetry for chiral symmetric quantum walks. Quantum Inf. Process. 18, 363b (2019)

    Article  MathSciNet  ADS  Google Scholar 

  20. Suzuki, A., Tanaka, Y.: The Witten index for 1D supersymmetric quantum walks with anisotropic coins. Quantum Inf. Process. 18, 377 (2019)

    Article  MathSciNet  ADS  Google Scholar 

  21. Tanaka, Y.: A constructive approach to topological invariants for one-dimensional strictly local operators. J. Math. Anal. Appl. 500, 125072 (2021)

    Article  MathSciNet  Google Scholar 

  22. Venegas-Andraca, S.E.: Quantum walks: a comprehensive review. Quantum Inf. Process. 11, 1015–1106 (2012)

    Article  MathSciNet  Google Scholar 

  23. Zidan, M.: A novel quantum computing model based on entanglement degree. Mod. Phys. Lett. B 34, 2050401 (2020)

    Article  MathSciNet  ADS  Google Scholar 

  24. Zidan, M., Abdel-Aty, A.-H., El-Sadek, A., et al.: Low-cost autonomous perceptron neural network inspired by quantum computation. AIP Conf. Proc. 1905, 020005 (2017)

    Article  Google Scholar 

  25. Zidan, M., Abdel-Aty, A.-H., El-shafei, M., et al.: Quantum classification algorithm based on competitive learning neural network and entanglement measure. Appl. Sci. 9, 1277 (2019)

    Article  Google Scholar 

  26. Zidan, M., Abdel-Aty, A.-H., Nguyene, D.M., et al.: A quantum algorithm based on entanglement measure for classifying Boolean multivariate function into novel hidden classes. Results Phys. 15, 102549 (2019)

    Article  Google Scholar 

  27. Zidan, M., Eleuch, H., Abdel-Aty, M.: Non-classical computing problems: Toward novel type of quantum computing problems. Results Phys. 21, 103536 (2021)

    Article  Google Scholar 

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Correspondence to Hiromichi Ohno.

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Narimatsu, A., Ohno, H. & Wada, K. Unitary equivalence classes of split-step quantum walks. Quantum Inf Process 20, 368 (2021). https://doi.org/10.1007/s11128-021-03323-6

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