A blueprint for robust, high-temperature quantum entanglement with PT-symmetric molecular optomechanics

Abstract: We introduce and conduct a theoretical analysis of a $\mathcal{PT}$-symmetric double-cavity molecular optomechanical (McOM) system, presenting a framework for generating multipartite quantum entanglement that is both robust and highly adjustable. The system leverages a sophisticated synergy of collective molecular enhancement, nonreciprocal directional coupling, and engineered $\mathcal{PT}$-symmetric dissipation. A central finding is the exceptional thermal resilience of this entanglement, which persists robustly at and well above room temperature, with a practical operational ceiling limited by material stability around \SI{700}{\kelvin}. This remarkable resilience, driven by ultra-high-frequency molecular vibrations and collective $\sqrt{N}$ enhancement, positions our system as a leading candidate for developing robust, high-temperature quantum technologies. Notably, our work directly addresses the performance trade-offs inherent in nonlinear enhancement schemes. By employing a two-collective-mode model to explicitly investigate vibration-vibration correlations, our $\mathcal{PT}$-symmetric architecture achieves a balanced and powerful enhancement across all investigated bipartite entanglement channels: inter-cavity ($E_{ac}$), cavity-molecule ($E_{aB_1}$, $E_{cB_2}$), and critically, vibration-vibration ($E_{B_1B_2}$). These findings, rigorously validated within stable operational regimes, establish $\mathcal{PT}$-symmetric McOM as a versatile platform for engineering advanced quantum information technologies