Abstract
In [A.W. Harrow and R.A. Low, Commun. Math. Phys. 291(1):257–302 (2009)], it was shown that a quantum circuit composed of random 2-qubit gates converges to an approximate quantum 2-design in polynomial time. We point out and correct a flaw in one of the paper’s main arguments. Our alternative argument highlights the role played by transpositions induced by the random gates in achieving convergence.
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Ambainis, A., Emerson, J.: Quantum t-designs: t-wise independence in the quantum world. In: Proceedings of the 22nd Annual IEEE Conference on Computational Complexity, Los Alanitos, CA: IEEE, 2007, pp. 129–140
Emerson J., Weinstein Y.S., Saraceno M., Lloyd S., Cory D.G.: Pseudo-random unitary operators for quantum information processing. Science 302, 2098 (2003)
Hayden P., Leung D., Shor P.W., Winter A.: Randomizing quantum states: Constructions and applications. Commun. Math. Phy. 250(2), 371–391 (2004)
Bendersky A., Pastawski F., Paz J.P.: Selective and efficient estimation of parameters for quantum process tomography. Phys. Rev. Lett. 100(19), 190403 (2008)
Harrow A., Hayden P., Leung D.: Superdense coding of quantum states. Phys. Rev. Lett. 92(18), 187901 (2004)
Harrow A.W., Low R.A.: Random quantum circuits are approximate 2-designs. Commun. Math. Phy. 291(1), 257–302 (2009)
DiVincenzo D.P., Leung D.W., Terhal B.M.: Quantum Data Hiding. IEEE Trans. Inf Theory 48(3), 580–599 (2002)
Gross D., Audenaert K., Eisert J.: Evenly distributed unitaries: on the structure of unitary designs. J. Math. Phys. 48, 052104 (2007)
Dankert C., Cleve R., Emerson J., Livine E.: Exact and approximate unitary 2-designs and their application to fidelity estimation. Phys. Rev. A 80(1), 012304 (2009)
Brown W., Viola L.: Convergence rates for arbitrary statistical moments of random quantum circuits. Phys. Rev. Lett. 104, 250501 (2010)
Dahlsten O.C.O., Oliveira R., Plenio M.B.: The emergence of typical entanglement in two-party random processes. J. Phys. A-Math. Theo. 40, 8081–8108 (2007)
Oliveira R., Dahlsten O.C.O., Plenio M.B.: Generic entanglement can be generated efficiently. Phys. Rev. Lett. 98, 130502 (2007)
Feller W.: An Introduction to Probability Theory and Its Applications. Volume 1. New York, Wiley, 3rd edition, (1968)
Levin, D.A., Peres, Y., Wilmer, E.L.: Markov Chains and Mixing Times: With a Chapter on Coupling from the Past by James G. Propp and David B. Wilson. Providence, RI: Amer. Math. Soc., 2008
Aldous D., Diaconis P.: Shuffling cards and stopping times. The American Mathematical Monthly 93(5), 333–348 (1986)
Diaconis P., Shahshahani M.: Generating a random permutation with random transpositions. Probability Theory and Related Fields 57(2), 159–179 (1981)
Diaconis, P.: Group representations in probability and statistics. Hayward, CA: Inst. Math. Stat., 1988
Knuth D.E.: The art of computer programming, Vol. 2: Seminumerical algorithms. Reading, MA, Addison-Wesley, 3rd edition (1997)
Boyd S., Diaconis P., Parrilo P., Xiao L.: Symmetry Analysis of Reversible Markov Chains. Internet Mathematics 2(1), 31 (2005)
Diniz, I. Tuche de A.: Algoritmos quânticos para a geração de unitários pseudo-aleatórios. Master’s thesis, Universidade Federal Fluminense, Brazil, 2009
Hoeffding W.: Probability inequalities for sums of bounded random variables. J. Amer. Stat. Assoc. 58, 13–30 (1963)
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Communicated by M.B. Ruskai
This comment refers to doi:10.1007/s00220-009-0873-6.
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Diniz, I.T., Jonathan, D. Comment on “Random Quantum Circuits are Approximate 2-designs” by A.W. Harrow and R.A. Low (Commun. Math. Phys. 291, 257–302 (2009)). Commun. Math. Phys. 304, 281–293 (2011). https://doi.org/10.1007/s00220-011-1217-x
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DOI: https://doi.org/10.1007/s00220-011-1217-x