Coupling two charge qubits

Pashkin, Y and Yamamoto, T and Astafiev, O and Nakamura, Y and Averin, Dmitri and Tsai, J (2003) Coupling two charge qubits. NEC Res. Develop, 44. pp. 273-277.

Abstract

We demonstrate a Josephson circuit consisting of two electrostatically coupled charge quantum bits (qubits). Using a pulse technique, we coherently mix quantum states and observe quantum oscillation, the spectrum of which reflects interaction between the qubits. Our results demonstrate feasibility of coupling multiple solid-state qubits, and indicate the existence of entangled two-qubit states.