Abstract
We investigate the transport properties and entanglement between spin and position of one-dimensional quantum walks starting from a qubit over position states following a delta-like (local state) and Gaussian (delocalized state) distributions. We find out that if the initial state is delocalized enough and a NOT gate reflects this state backwards, then the interference pattern extinguishes the position dispersion without preventing the propagation of the state. This effect allows the creation of a Trojan wave packet, a non-spreading and non-stationary double-peak quantum state.
Similar content being viewed by others
References
J.P. Emery, F. Marzari, A. Morbidelli, L.M. French, T. Grav. The complex history of Trojan asteroids. Asteroids IV (University of Arizona Press, Tucson, 2015)
I. Bialynicki-Birula, M. Kaliński, J.H. Eberly, Lagrange Equilibrium Points in Celestial Mechanics and Nonspreading Wave Packets for Strongly Driven Rydberg Electrons. Phys. Rev. Lett. 73, 1777 (1994)
B. Wyker, S. Ye, F.B. Dunning, S. Yoshida, C.O. Reinhold, J. Burgdörfer, Creating and transporting trojan wave packets. Phys. Rev. Lett. 108, 043001 (2012)
Y. Aharonov, L. Davidovich, N. Zagury, Quantum random walks. Phys. Rev. A. 48, 1687 (1993)
J. Kempe, Quantum random walks: an introductory overview. Contemp. Phys. 44, 307 (2003)
S.E. Venegas-Andraca, Quantum walks: a comprehensive review. Quantum Inf. Process. 11, 1015 (2012)
N. Shenvi, J. Kempe, K.B. Whaley, Quantum random-walk search algorithm. Phys. Rev. A. 67, 052307 (2003)
A.M. Childs, Universal computation by quantum walk. Phys. Rev. Lett. 102, 180501 (2009)
N.B. Lovett, S. Cooper, M. Everitt, M. Trevers, V. Kendon, Universal quantum computation using the discrete-time quantum walk. Phys. Rev. A. 81, 042330 (2010)
J.R. Busemeyer, Z. Wang, J.T. Townsend, Quantum dynamics of human decision-making. J. Math. Psychol. 50, 220 (2006)
G.S. Engel, T.R. Calhoun, E.L. Read, T.K. Ahn, T. Mančcal, Y.C. Cheng, R.E. Blankenship, G.R. Fleming, Evidence for wavelike energy transfer through quantum coherence in photosynthetic systems. Nature. 446, 782 (2007)
G. Di Molfetta, A. Pérez, Quantum walks as simulators of neutrino oscillations in a vacuum and matter. New J. Phys. 10, 103038 (2016)
Y. Wang, Y. Shang, P. Xue, Generalized teleportation by quantum walks. Quantum Inf. Process. 16, 221 (2017)
J. Wang, K. Manouchehri, Physical implementation of quantum walks. Springer (2013)
M.A. Nielsen, I.L. Chuang, Quantum computation and quantum information. Cambridge University Press (2010)
Z.J. Li, J.A. Izaac, J.B. Wang, Position-defect-induced reflection, trapping, transmission, and resonance in quantum walks. Phys. Rev. A. 87, 012314 (2013)
C.H. Bennett, H.J. Bernstein, S. Popescu, B. Schumacher, Concentrating partial entanglement by local operations. Phys. Rev. A. 53, 2046 (1996)
A.C. Orthey, E.P.M. Amorim, Connecting spreading and entanglement in quantum walks. arXiv:1807.01361 (2018)
A.C. Orthey, E.P.M. Amorim, Asymptotic entanglement in quantum walks from delocalized initial states. Quantum Inf. Process. 16, 224 (2017)
G. Abal, R. Siri, A. Romanelli, R. Donangelo, Quantum walk on the line: entanglement and nonlocal initial conditions. Phys. Rev. A. 73, 042302 (2006)
G. Abal, R. Siri, A. Romanelli, R. Donangelo, Erratum: Quantum walk on the line: entanglement and non-local initial conditions [phys. rev. a 73, 042302 (2006)]. Phys. Rev. A. 73, 069905(E) (2006)
A. Kempf, R. Portugal, Group velocity of discrete-time quantum walks. Phys. Rev. A. 79, 052317 (2009)
A.C. Orthey, E.P.M. Amorim, Weak disorder enhancing the production of entanglement in quantum walks. arXiv:1711.09246 (2018)
R. Vieira, E.P.M. Amorim, G. Rigolin, Dynamically disordered quantum walk as a maximal entanglement generator. Phys. Rev. Lett. 111, 180503 (2013)
R. Vieira, E.P.M. Amorim, G. Rigolin, Entangling power of disordered quantum walks. Phys. Rev. A. 89, 042307 (2014)
A. Streltsov, U. Singh, H.S. Dhar, M.N. Bera, G. Adesso, Measuring quantum coherence with entanglement. Phys. Rev. Lett. 115, 020403 (2015)
Acknowledgements
HSG and EPMA thank Janice Longo for her careful reading of the manuscript.
Funding
This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Ghizoni, H.S., Amorim, E.P.M. Trojan Quantum Walks. Braz J Phys 49, 168–172 (2019). https://doi.org/10.1007/s13538-019-00638-9
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13538-019-00638-9