Quantum deficits and correlations of two superconducting charge qubits

Abstract

Motivated by recent experiments [Pashkin et al. Nature, \textbf{421}, 823 (2003)] which showed coherent oscillations of two superconducting qubits system, we consider a system of two charge qubits coupled to a common stripline microwave resonator. We discuss the separable and entangled behavior as well as the quantum and classical information deficits. Numerical computation of these quantities for several regimes is performed. We find that for less entangled states the partner can extract much more information by means of classical communication and local operations