Abstract

The flux qubit is often considered as a major design for the future of quantum integrated circuits and its properties have triggered intense interest in the last decade [1-2]. This superconducting circuit behaves as a two-level system, each level being characterized by the direction of a macroscopic permanent current flowing in the loop of the qubit. The permanent current, typically of the order of several hundreds of nAs, generates a large magnetic dipole, which offers interesting prospects for hybrid quantum circuits [3]. However, the flux qubit suffers from limited and irreproducible lifetimes which partially prevent these potential applications. Recently, a novel architecture where qubits are placed in a three dimensional cavity was introduced for transmon qubit [4]. It was shown that coherence properties can be greatly improved.

© 2014 Optical Society of America