Efficient scheme for generating a <i>W</i>-type optical entangled cat state

Abstract

W-type optical entangled cat states play a crucial role in quantum information processing, quantum communication, and quantum technology. In this Letter, we propose an efficient protocol for preparing a W-type optical entangled cat state in circuit quantum electrodynamics (QED). The W-state preparation requires only a few basic operations. The system complexity is substantially reduced by using only one coupler qutrit. Our numerical simulation demonstrates that the high-fidelity preparation of the W-type optical entangled cat state is feasible with current circuit QED technology. This proposal is universal and can be extended to generate the W-type optical entangled cat state, by employing three microwave or optical cavities coupled to a natural or artificial three-level atom.