A tunable coupler with ScS quantum point contact to mediate strong interaction between flux qubits

Abstract

In this paper we propose a kind of quantum inductance couplers (QUINC) which represents a superconducting loop closed by ScS quantum point contact, operating in deep quantum low-temperature regime to provide tunable (Ising-type) ZZ interaction between flux qubits. This coupler is shown to be well tunable by an external control magnetic flux and to provide large inter-qubit interaction energies $|J/k_{\mathrm{B}}|\simeq 1$ K thus being very promising as a qubit-coupling device in a quantum register as well as for studying fundamental low-temperature quantum phenomena. Some entanglement measures of a two-qubit system are analyzed as functions of inter-qubit interaction strength.

8 pages, 5 figures; figure, text, references added

References in corpus (3)

• Spectroscopy on two coupled flux qubits
• Mediated tunable coupling of flux qubits
• Quantum superposition of three macroscopic states and superconducting qutrit detector