Based on a quantum analysis of two capacitively coupled current-biased Josephson junctions, we propose two fundamental two-qubit quantum logic gates. Each of these gates, when supplemented by single-qubit operations, is sufficient for universal quantum computation. Numerical solutions of the time-dependent Schroedinger equation demonstrate that these operations can be performed with good fidelity.
@article{arxiv.quant-ph/0303002,
title = {Quantum logic gates for coupled superconducting phase qubits},
author = {Frederick W. Strauch and Philip R. Johnson and Alex J. Dragt and C. J. Lobb and J. R. Anderson and F. C. Wellstood},
journal= {arXiv preprint arXiv:quant-ph/0303002},
year = {2009}
}