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      https://www.ias.ac.in/article/fulltext/pram/088/03/0045

    • Keywords

       

      Quantum information; quantum random walk; quantum computation

    • Abstract

       

      In this article we present an effective Hamiltonian approach for discrete time quantum random walk. A form of the Hamiltonian for one-dimensional quantum walk has been prescribed, utilizing the fact that Hamiltoniansare generators of time translations. Then an attempt has been made to generalize the techniques to higher dimensions. We find that the Hamiltonian can be written as the sum of a Weyl Hamiltonian and a Dirac comb potential. The time evolution operator obtained from this prescribed Hamiltonian is in complete agreement with that of the standard approach. But in higher dimension we find that the time evolution operator is additive, instead of being multiplicative (see Chandrashekar, $\it{Sci. Rep}$. 3, 2829 (2013)). We showed that in the case of two-step walk, the time evolution operator effectively can have multiplicative form. In the case of a square lattice, quantum walk has been studied computationally for different coins and the results for both the additive and the multiplicative approaches have been compared. Using the graphene Hamiltonian, the walk has been studied on a graphene lattice and we conclude the preference of additive approach over the multiplicative one.

    • Author Affiliations

       

      DEBAJYOTI SARKAR1 NILADRI PAUL1 KAUSHIK BHATTACHARYA2 TARUN KANTI GHOSH2

      1. Inter-University Centre for Astronomy and Astrophysics, Ganeshkhind, Pune 411 007, India
      2. Department of Physics, Indian Institute of Technology, Kanpur 208 016, India
    • Dates

       
  • Pramana – Journal of Physics | News

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