Tripartite Entanglement Generation in Atom-Coupled Dual Microresonators System

TL;DR

This work addresses the generation and control of genuine tripartite entanglement in a hybrid cavity QED system consisting of two linearly coupled resonators, one of which interacts with a two-level atom. It combines a weak-drive analytical framework with Lindblad-dynamics simulations to derive steady-state solutions and to define a tripartite entanglement witness based on concurrence fill, using reduced-state amplitudes $c_0,c_1,c_2,c_3$ in the single-excitation manifold. The main contributions are: (i) deriving closed-form expressions for the tripartite concurrences and the concurrence-fill measure, (ii) identifying resonance conditions and optimal couplings $g$ and $J$ that maximize genuine tripartite entanglement, and (iii) demonstrating, via numerical validation, the transition from localized Jaynes–Cummings correlations to a delocalized, steady-state tripartite entangled network as detuning, drive, and dissipation are tuned. These results establish a clear route to engineering steady-state multipartite quantum resources in coupled-cavity networks, with implications for quantum networking and distributed quantum information processing, and provide practical guidance for photonic state routing in scalable architectures. The study highlights the balance between coherent interaction and dissipation as a lever to control multipartite correlations in hybrid quantum systems, encapsulated by the tripartite measure $\mathcal{F}_{123}$ built from $\mathcal{C}_{1(23)}$, $\mathcal{C}_{2(31)}$, and $\mathcal{C}_{3(12)}$.

Abstract

In this work, we investigate the emergence and control of genuine tripartite entanglement in a hybrid cavity quantum electrodynamics architecture consisting of two linearly coupled single mode resonators, one of which interacts coherently with a two level atom. An analytical framework is developed in a weak driving regime, where the system dynamically supports a delocalized hybrid excitation shared by the two photonic modes and the atomic degree of freedom. Tripartite concurrence fill has been used to characterize and identify parameter regimes of maximal multipartite quantum correlation that can be generated in this model. Additionally, we demonstrate how dissipative rates and detuning asymmetries govern the conversion of bipartite entanglement into a genuinely tripartite state, establishing a controllable transition from localized Jaynes Cummings correlations to delocalized photonic atomic entanglement networks. These findings outline a clear route to engineering steady state multipartite quantum resources in coupled cavity QED platforms, with direct relevance to quantum networking, distributed quantum information processing, and photonic state routing in scalable quantum architectures.

Figures (8)

• Figure 1: Schematic diagram of the proposed model to generate tripartite entanglement.
• Figure 2: Variation of bipartite concurrence with normalized detuning under different coupling regimes. (a)Steady-state concurrence as a function of normalized detuning for atom–resonator coupling strengths. (b)Surface plot of concurrence as a function of normalized detuning and coupling strength. (c)Concurrence as a function of normalized detuning for two photon-hopping strengths. (d)Surface plot of concurrence as a function of normalized detuning and coupling constant J.
• Figure 3: (a) Variation of the bipartite concurrences as a function of normalized detuning in the hybrid regime where both the atom–cavity coupling and the inter-cavity hopping are finite. (b)Dependence of the three concurrences on the normalized atom–cavity coupling at fixed detuning.
• Figure 4: Surface plots of bipartite concurrences as functions of normalized detuning and atom–cavity coupling strength g.
• Figure 5: Surface plots of bipartite concurrences as functions of normalized detuning and drive strength for nonzero atom–cavity (g) and inter-cavity (J) couplings. The bright regions mark the optimal drive, where coherent excitation exchange among the atom and both cavities generates maximal hybrid entanglement.