  Twisted rapid passage is a type of non-adiabatic rapid passage that generates
controllable quantum interference effects that were first observed
experimentally in 2003. It is shown that twisted rapid passage sweeps can be
used to implement a universal set of quantum gates that operate with
high-fidelity. The gate set consists of the Hadamard and NOT gates, together
with variants of the phase, pi/8, and controlled-phase gates. For each gate g
in the universal set, sweep parameter values are provided which numerical
simulations indicate will produce a unitary operation that approximates g with
error probability less than 10**(-4). Note that all gates in the universal set
are implemented using a single family of control-field, and the error
probability for each gate falls below the rough-and-ready estimate for the
accuracy threshold of 10**(-4).
