2001/07/03 by Jérémie Roland, Jeremie Roland, Nicolas J. Cerf · 1 voice · 64 citations
Computer Science · Physics and Astronomy · #Computability, Logic, AI Algorithms #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #quant-ph
paper · pdf · doi:10.1103/physreva.65.042308
published as Phys. Rev. A 65, 042308 (2002) · 4 pages RevTex, 2 encapsulated Postscript figures
arxiv created 2001/07/03 · openalex publication_date 2002/03/26 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The adiabatic theorem has been recently used to design quantum algorithms of a new kind, where the quantum computer evolves slowly enough so that it remains near its instantaneous ground state which tends to the solution [Farhi et al., quant-ph/0001106]. We apply this time-dependent Hamiltonian approach to the Grover's problem, i. e., searching a marked item in an unstructured database. We find that, by adjusting the evolution rate of the Hamiltonian so as to keep the evolution adiabatic on each infinitesimal time interval, the total running time is of order √(N), where N is the number of items in the database. We thus recover the advantage of Grover's standard algorithm as compared to a classical search, scaling as N. This is in contrast with the constant-rate adiabatic approach developed by Farhi et al., where the requirement of adiabaticity is expressed only globally, resulting in a time of order N.