%0 Journal Article
%J Physical Review LettersPhys. Rev. Lett.
%D 2005
%T Asymptotically Optimal Quantum Circuits for d-Level Systems
%A Bullock,Stephen S.
%A O’Leary,Dianne P.
%A Brennen,Gavin K.
%X Scalability of a quantum computation requires that the information be processed on multiple subsystems. However, it is unclear how the complexity of a quantum algorithm, quantified by the number of entangling gates, depends on the subsystem size. We examine the quantum circuit complexity for exactly universal computation on many d-level systems (qudits). Both a lower bound and a constructive upper bound on the number of two-qudit gates result, proving a sharp asymptotic of Θ(d2n) gates. This closes the complexity question for all d-level systems (d finite). The optimal asymptotic applies to systems with locality constraints, e.g., nearest neighbor interactions.
%B Physical Review LettersPhys. Rev. Lett.
%V 94
%P 230502 - 230502
%8 2005/06/14/
%G eng
%U http://link.aps.org/doi/10.1103/PhysRevLett.94.230502
%N 23
%R 10.1103/PhysRevLett.94.230502