High-fidelity universal quantum gates through quantum interference

Numerical simulation results are presented which suggest that a class of non-adiabatic rapid passage sweeps first realized experimentally in 1991, and which give rise to controllable quantum interference effects observed using NMR in 2003, should be capable of implementing a universal set of quantum gates G(u) that operate with high-fidelity. G(u) consists of the Hadamard and NOT gates, together with variants of the phase, pi/8, and controlled-phase gates. Sweep parameter values are provided which simulations indicate will produce the different gates in G(u), and for each gate, yield an operation with error probability P-e < 10(-4). The simulations suggest that the universal gate set produced by these rapid passage sweeps show promise as possible elements of a fault-tolerant scheme for quantum computing.