Artificial intelligence empowered Terahertz communications for 6G networks challenges enablers and research gaps

Abstract The move toward 6G wireless networks requires a fundamental shift toward integrating Terahertz communications with pervasive Artificial Intelligence. This paper provides a comprehensive systematic review of the synergies between these two pillars, structured to bridge the gap between hardware constraints and algorithmic optimization. By following a rigorous PRISMA-based methodology, the requirements are established, and key performance indicators are defined in the 6G era. The paper discusses the physical layer architecture, examining Ultra- Massive MIMO configurations and evolution toward novel metasurface designs. The study extends the analysis to network intelligence, evaluating AI native solutions for radio resource management, beamforming, and signal processing while specifically addressing the critical challenges of signalling overhead and model lifecycle management as discussed in recent 3GPP frameworks. Additionally, the role of emerging enablers, including digital twins, blockchain, and integrated sensing communication is explored within the context of high bandwidth applications like the metaverse and space air-ground integrated networks. Finally, this review provides current literature to define a tripartite framework of research gaps, mapping existing limitations to specific open problems. By providing this holistic structural overview, the work serves as a technical roadmap for the deployment of intelligent, high-frequency 6G ecosystems. This work aligns with UN Sustainable Development Goals SDG 9 (Industry, Innovation and Infrastructure) by advancing AI-native Terahertz-enabled 6G communication architectures, and SDG 11 (Sustainable Cities and Communities) through intelligent, high-capacity connectivity for future smart and digital ecosystems.