HIGH-FIDELITY UNIVERSAL QUANTUM GATES THROUGH GROUP-SYMMETRIZED RAPID PASSAGE

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 G(U) that operate with high-fidelity. The gate set G(U) consists of the Hadamard and NOT gates, together with variants of the phase, pi/8, and controlled-phase gates. For each gate g in G(U), sweep parameter values are provided which simulations indicate will produce a unitary operation that approximates g with error probability P-e < 10(-4). Note that all gates in G(U) 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 P-a similar to 10(-4).