TY - JOUR
T1 - Asymptotically Optimal Quantum Circuits for d-Level Systems
JF - Physical Review LettersPhys. Rev. Lett.
Y1 - 2005
A1 - Bullock,Stephen S.
A1 - O’Leary,Dianne P.
A1 - Brennen,Gavin K.
AB - 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.
VL - 94
UR - http://link.aps.org/doi/10.1103/PhysRevLett.94.230502
CP - 23
M3 - 10.1103/PhysRevLett.94.230502
ER -