Abstract
We consider quantum dynamical systems specified by a unitary operator U and an initial state vector \({\phi}\). In each step the unitary is followed by a projective measurement checking whether the system has returned to the initial state. We call the system recurrent if this eventually happens with probability one. We show that recurrence is equivalent to the absence of an absolutely continuous part from the spectral measure of U with respect to \({\phi}\). We also show that in the recurrent case the expected first return time is an integer or infinite, for which we give a topological interpretation. A key role in our theory is played by the first arrival amplitudes, which turn out to be the (complex conjugated) Taylor coefficients of the Schur function of the spectral measure. On the one hand, this provides a direct dynamical interpretation of these coefficients; on the other hand it links our definition of first return times to a large body of mathematical literature.
Similar content being viewed by others
References
Ahlbrecht, A., Alberti, A., Meschede, D., Scholz, V.B., Werner, A.H., Werner, R.F.: Bound molecules in an interacting quantum walk. http://arxiv.org/abs/1105.1051v2 [quant-ph], 2011
Ahlbrecht, A., Cedzich, C., Matjeschk, R., Scholz, V.B., Werner, A.H., Werner, R.F.: Asymptotic behavior of quantum walks with spatio-temporal coin fluctuations. http://arxiv.org/abs/1201.4839v1 [quant-ph], 2012
Ahlbrecht A., Scholz V.B., Werner A.H.: Disordered quantum walks in one lattice dimension. J. Math. Phys. 52, 102201 (2011)
Ahlbrecht A., Vogts H., Werner A.H., Werner R.F.: Asymptotic evolution of quantum walks with random coin. J. Math. Phys. 52, 042201 (2011)
Allcock, G.R.: The time of arrival in quantum mechanics. Ann. Phys. (N.Y.) 53, 253–285, 286–310, 311–348 (1969)
Ambainis, A., Bach, E., Nayak, A., Vishwanath, A., Watrous, J.: One dimentional quantum walks. In: 33rd Annual ACM STOC. ACM, NY, pp 60–69 (2001)
Bach E., Coppersmith S., Goldschen M.P., Joynt R., Watrous J.: One-dimentional quantum walks with absorbing boundaries. J Comput. Syst. Sci. 69(4), 562–592 (2004)
Brassard G.: Quantum computing: The end of classical cryptography?. SIGACT News 25, 15–21 (1994)
Brezis, H.: New questions related to the topological degree. In: Etingof, P., Retakh, V., Singer, I.M. editors, The Unity of Mathematics, Volume 244 of Progress in Mathematics, Boston: Birkhäuser, 2006, pp. 137–154
Cantero M.J., Grünbaum F.A., Moral L., Velázquez L.: Matrix-valued Szegő polynomials and quantum random walks. Comm. Pure Appl. Math. 63(4), 464–507 (2010)
Cantero M.J., Grünbaum F.A., Moral L., Velázquez L.: One-dimensional quantum walks with one defect. Rev. Math. Phys. 24, 1250002 (2012)
Cantero M.J., Moral L., Velázquez L.: Five-diagonal matrices and zeros of orthogonal polynomials on the unit circle. Linear Algebra Appl. 362, 29–56 (2003)
Castrigiano D.P.L., Mutze U.: Repeated measurements in quantum theory. Phys. Rev. A. 30, 2210–2220 (1984)
Feynman, R.: The Feynman Lecture of physics; III: Quantum Mechanics. Reading, MA: Addison-wesley, 1966
Frostman O.: Potential d’équilibre et capacité des ensembles avec quelques applications a la theorie des fonctions. Medd. Lunds Univ. Mat. Sem. 3, 1–118 (1935)
Garnett J.B.: Bounded analytic functions. Academic Press, New York-London (1981)
: Bound states and scattered states for contraction semigroups. Acta Appl. Math. 4, 93–98 (1985)
Grimmett G., Janson S., Scudo P.F.: Weak limits for quantum random walks. Phys. Rev. E 69, 026119 (2004)
Grünbaum, F.A., Velázquez, L.: The quantum walk of F. Riesz. In: Cucker, F., Krick, T., Pinkus, A., Szanto, A. (eds.) Proceedings of FoCAM2011. London Mathematical Society Lecture Notes Series, 403, pp. 93–112. Nov. 2012, available at http://arxiv.org/abs/1111.6630, 2011
Karlin S., Taylor H.M.: A first course in stochastic processes. Academic Press, New York-London (1975)
Karski M., Förster L., Choi J.M., Alt W., Widera A., Meschede D.: Nearest-Neighbor Detection of Atoms in a 1D Optical Lattice by Fluorescence Imaging. Phys. Rev. Lett. 102, 053001 (2009)
Kiukas, J., Ruschhaupt, A., Schmidt, P.O., Werner, R.F.: Exact energy-time uncertainty relation for arrival time by absorption. http://arxiv.org/abs/1109.5087v1 [quant-ph], 2011
Krushchev S.: Schur’s algorithm, orthogonal polynomials and convergence of Wall’s continued fractions in \({\mathcal{L}^{2}(\mathbb {T})}\). J. Approx. Theory 108, 161–248 (2001)
Last Y.: Quantum dynamics and decomposition of singular continuous spectra. J. Funct. Anal. 142, 406–445 (1996)
Macdonald I.G.: Symmetric functions and Hall polynomials. Oxford University Press, New York (1995)
Mensky, M.B.: Continuous Quantum measurements and path integrals. Bristol-Philadelphia, PA-Muenchen: IOP Publishing, 1993
Pólya G.: Über eine Aufgabe der Wahrscheinlichkeitsrechnung betreffend die Irrfahrt im Straßennetz. Math. Ann. 84, 149–160 (1921)
Reed M., Simon B.: Methods of Modern Mathematical Physics III: Scattering Theory. Academic Press, London-New York (1979)
Riesz F.: Über die Fourierkoeffizienten einer stetigen Funktion von beschränkter Schwankung. Math. Zeit. 2(3-4), 312–315 (1918)
Schur J.: Über Potenzreihen, die im Innern des Einheitskreises beschränkt sind; fortsetzung. J. Reine Ang. Math. 147, 205–232 (1917)
Schur J.: Über Potenzreihen, die im Innern des Einheitskreises beschränkt sind. J. Reine Ang. Math. 148, 122–145 (1918)
Simon, B.: Orthogonal polynomials on the unit circle, Vol. 1. Providence, RI: Amer. Math. Soc., 2005
Simon, B.: Orthogonal polynomials on the unit circle, Vol. 2. Providence, RI: Amer. Math. Soc., 2005
Simon B.: CMV matrices: Five years after. J. Comp. Appl. Math. 208(1), 120–154 (2007)
Štefaňák M., Jex I., Kiss T.: Recurrence and Pólya number of quantum walks. Phys. Rev. Lett. 100, 020501 (2008)
Verblunsky, S.: On positive harmonic functions: A contribution to the algebra of Fourier series. Proc. London Math. Soc. s.2, 38, 125–157 (1935)
Watkins D.S.: Some perspectives on the eigenvalue problem. SIAM Rev. 35, 430–471 (1993)
Werner R.F.: Arrival time observables in quantum mechanics. Ann. Inst. H. Poincaré Phys. Théor. 47, 429–449 (1987)
Yosida K., Kakutani S.: Markoff process with an enumerable infinite number of states. Jap. J. Math 16, 47–55 (1940)
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by S. Zelditch
Rights and permissions
About this article
Cite this article
Grünbaum, F.A., Velázquez, L., Werner, A.H. et al. Recurrence for Discrete Time Unitary Evolutions. Commun. Math. Phys. 320, 543–569 (2013). https://doi.org/10.1007/s00220-012-1645-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00220-012-1645-2