Tunable coupling of qubits: nonadiabatic corrections

Abstract

We analyze the coupling of qubits mediated by a tunable and fast element beyond the adiabatic approximation. The nonadiabatic corrections are important and even dominant in parts of the relevant parameter range. As an example, we consider the tunable capacitive coupling between two charge qubits mediated by a gated Josephson junction, as suggested by Averin and Bruder. The nonadiabatic, inductive contribution persists when the capacitive coupling is tuned to zero. On the other hand, the total coupling can be turned off (in the rotating wave approximation) if the qubits are operated at symmetry points.

7 pages, 2 figures, accepted in Europhysics Letters

References in corpus (4)

• Spectroscopy on two coupled flux qubits
• Parametric coupling for superconducting qubits
• Tunable coupling scheme for flux qubits at the optimal point
• Mediated tunable coupling of flux qubits

Cited by in corpus (5)

• Interqubit coupling mediated by a high-excitation-energy quantum object
• Geometrical spin dephasing in quantum dots
• Long-range coupling and scalable architecture for superconducting flux qubits
• Spin dephasing due to a random Berry phase
• Emergence of a negative charging energy in a metallic dot capacitively coupled to a superconducting island