Tunable interaction of superconducting flux qubits in circuit QED

TL;DR

This paper proposes a method to achieve tunable, cavity-insensitive interactions between superconducting flux qubits in circuit QED, enabling controlled entanglement generation with suppressed decay.

Contribution

It introduces a novel scheme for tunable qubit interactions using three-level flux qubits and phase-controlled driving, enhancing control and robustness in circuit QED.

Findings

Interaction is insensitive to cavity field state.

Effective suppression of excited state decay.

Feasibility of generating entangled states under decoherence.

Abstract

We propose to implement tunable interaction of superconducting flux qubits with cavity-assisted interaction and strong driving. The qubits have a three-level Lambda configuration, and the decay of the excited state will be greatly suppressed due to the effective large detuning. The implemented interaction is insensitive to the cavity field state and can be controlled by modulating the phase difference of the driving fields of the qubits. In particular, our scheme is based on the typical circuit QED setup and thus will provide a simple method towards the tunable interaction of superconducting qubits. Finally, we consider the generation of two and four qubits entangled states with the constructed interaction under the influence of typical decoherence effects.