
Received: September 30, 2008
Published: July 1, 2009
Abstract: [Plain Text Version]
This is a comment on the article “A Quantum Algorithm for the Hamiltonian NAND Tree” by Edward Farhi, Jeffrey Goldstone, and Sam Gutmann, Theory of Computing 4 (2008) 169--190. That paper gave a quantum algorithm for evaluating nand trees with running time O(√N) in the Hamiltonian query model. In this note, we point out that their algorithm can be converted into an algorithm using N½ + o(1) queries in the conventional (discrete) quantum query model.
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