Generating multi-atom entangled W states via light-matter interface based fusion mechanism

TL;DR

This paper proposes a method to generate large multi-atom W states by fusing smaller W states using a light-matter interaction in cavity QED, avoiding complex gates and feasible with current technology.

Contribution

It introduces a novel fusion mechanism for W states in cavity QED that simplifies the process and enhances scalability without requiring Fredkin gates.

Findings

Fusion of small W states into larger ones demonstrated

Feasibility analysis shows implementation with current technology

Avoids complex gate operations like Fredkin gate

Abstract

W state is a key resource in quantum communication. Fusion technology has been proven to be a good candidate for preparing a large-size W state from two or more small-size W states in linear optical system. It is of great importance to study how to fuse W states via light-matter interface. Here we show that it is possible to prepare large-size W-state networks using a fusion mechanism in cavity QED system. The detuned interaction between three atoms and a vacuum cavity mode constitute the main fusion mechanism, based on which two or three small-size atomic W states can be fused into a larger-size W state. If no excitation is detected from those three atoms, the remaining atoms are still in the product of two or three new W states, which can be re-fused. The complicated Fredkin gate used in the previous fusion schemes is avoided here. W states of size 2 can be fused as well. The feasibility analysis shows that our fusion processes maybe implementable with the current technology. Our results demonstrate how the light-matter interaction based fusion mechanism can be realized, and may become the starting point for the fusion of multipartite entanglement in cavity QED system.