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

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.

Multiatom Quantum Coherences in Micromasers as Fuel for Thermal and Nonthermal Machines

“…• Alternatively, W states can be generated via quan-tum feedback control [55] or at fusion-based lightmatter interfaces [56].…”

Fusion of entangled coherent W and GHZ states in cavity QED

“…quantum state fusion and expansion technique [41][42][43][44][45][46][47][48][49][50]. Although this new technique has been introduced for fusing atomic entangled states [51][52][53], it has not been introduced for fusing multi-mode entangled coherent states. So in this paper, we present a scheme for fusing multi-mode entangled coherent W states into larger W states.…”

Evolution of tripartite entangled states in a decohering environment and their experimental protection using dynamical decoupling

“…On the experimental front, tripartite entanglement was generated using photonic qubits and the robustness of W state entanglement was studied in optical systems [13][14][15][16]. The dynamics of multi-qubit entanglement under the influence of decoherence was experimentally characterized using a string of trapped ions [17] and in superconducting qubits [18].…”