Quantum computing with superconducting phase qubits

The superconducting phase qubit combines Josephson junctions into superconducting loops and defines one of the promising solid state device implementations for quantum computing. Here, we propose two hardware realizations for superconducting phase qubits, where the first is based on 2 phi -periodic s-wave-d-wave-s-wave Josephson junctions, while the second proposal involves five Josephson junctions arranged in a loop which is frustrated by a re-junction, a Josephson junction with a ground state characterized by a pi -phase shift across. (C) 2001 Elsevier Science B.V. All rights reserved.