Deriving Entropic Inequalities for Two Coupled Superconducting Circuits

Abstract

We discuss the known construction of two interacting superconducting circuits, based on Josephson junctions, that can be precisely engineered and easily controlled. In particular, we use the parametric excitation of two circuits, realized by an instant change of the qubit coupling, to study entropic and information properties of the density matrix of the composite system. The density matrix is obtained from the initial thermal state and is then analyzed in the approximation of small perturbation parameter and sufficiently low temperature. We also check the subadditivity condition for this system both for von Neumann and deformed entropies and look at the dependance of mutual information on the temperature of the system. Finally, we discuss the applicability of this approach to describe such system of two coupled superconducting qubits as harmonic oscillators with limited Hilbert space.

12 pages, 5 figures

References in corpus (4)

• On Testing Entropic Inequalities for Superconducting Qudit
• No signaling and strong subadditivity condition for tomographic q-entropy of single qudit states
• Photon generation from vacuum in non-stationary circuit QED
• Prospects for observing dynamical and anti- dynamical Casimir effects in circuit QED due to fast modulation of qubit parameters