Generation of GHZ entangled states of photons in multiple cavities via a superconducting qutrit or an atom through resonant interaction

TL;DR

This paper presents a fast, measurement-free method to generate GHZ entangled photon states across multiple cavities using a superconducting qutrit or an atom, leveraging resonant interactions for high fidelity.

Contribution

The method introduces the use of a qutrit as a coupler for resonant interactions, reducing operation time and decoherence effects compared to previous approaches.

Findings

Protocol achieves GHZ state generation efficiently

No measurement required during the process

Applicable to different physical systems like atoms or superconducting circuits

Abstract

We propose an efficient method to generate a GHZ entangled state of n photons in n microwave cavities (or resonators) via resonant interaction to a single superconducting qutrit. The deployment of a qutrit, instead of a qubit, as the coupler enables us to use resonant interactions exclusively for all qutrit-cavity and qutrit-pulse operations. This unique approach significantly shortens the time of operation which is advantageous to reducing the adverse effects of qutrit decoherence and cavity decay on fidelity of the protocol. Furthermore, the protocol involves no measurement on either the state of qutrit or cavity photons. We also show that the protocol can be generalized to other systems by replacing the superconducting qutrit coupler with different types of physical qutrit, such as an atom in the case of cavity QED, to accomplish the same task.