**Abstract: Fano Resonance in Epsilon-Near-Zero Media** On December 19, 2023, a research team led by Associate Professor Li Yue from the Department of Electronic Engineering at Tsinghua University published a groundbreaking study in *Physical Review Letters* titled "Fano Resonance in Epsilon-Near-Zero Media." This research marks the first observation of Fano resonance in epsilon-near-zero (ENZ) media, a class of materials with a dielectric constant close to zero. The discovery introduces a novel method for dispersion control in microwave and optical devices, potentially revolutionizing their on-chip integration. **Background: Understanding Fano Resonance and ENZ Media** Fano resonance is a well-known electromagnetic phenomenon characterized by asymmetric spectral lines resulting from the interaction between a discrete resonant state and a continuum of states. Over the decades, it has been extensively studied across various fields, including optics, atomic physics, condensed matter physics, and quantum information, due to its significant applications in advanced technologies such as photonic sensors, nanolasers, and quantum computing. ENZ media, on the other hand, are materials with a dielectric constant near zero, which exhibit unique electromagnetic properties. These properties make ENZ media particularly advantageous for miniaturized and shape-adaptive devices, offering a new platform for achieving small-scale and customizable Fano resonance. The research team at Tsinghua University discovered that ENZ media possess a unique weak coupling mechanism that aligns well with the continuous resonant states required for Fano resonance. By integrating dielectric resonant structures into ENZ media, they successfully introduced discrete resonant states, thereby observing Fano resonance in these materials. **Key Findings and Innovations** The study revealed two significant features of Fano resonance in ENZ media. First, the spectral lines of Fano resonance are a function of the magnetic permeability of the ENZ media. This finding allows for precise control of the Fano resonance spectrum by adjusting the magnetic permeability, providing a flexible and tunable approach to dispersion management. Second, ENZ media can induce Fano resonance at extremely small scales and arbitrary shapes, overcoming the size limitations of traditional Fano resonance devices. This breakthrough paves the way for the integration and miniaturization of Fano resonance devices, enhancing their practical applications. **Experimental Verification and Applications** The research team conducted experiments to verify these phenomena, demonstrating the feasibility and effectiveness of their approach. They further explored the potential applications of Fano resonance in ENZ media, particularly in the context of controlling the dispersion of electromagnetic devices. One notable application is the development of optical filters with electromagnetically induced transparency (EIT) characteristics. By leveraging the Fano resonance effect in ENZ media, researchers can achieve dispersion control through simple structural adjustments, which is crucial for the performance of lasers, all-optical switches, photonic sensors, and future photonic chips. **Team and Funding** The paper's first author is Yan Wendeng, a doctoral student at Tsinghua University since 2021. Associate Professor Li Yue serves as the corresponding author. Other contributors include Li Hao (2018 doctoral graduate), Qin Xu (2019 doctoral graduate), Fu Pengyu (2021 doctoral student), Li Peihang (2023 doctoral student), and Li Kaifeng (2024 doctoral student). The research was supported by Tsinghua University's Department of Electronic Engineering, the National Natural Science Foundation of China, and the National Key Research and Development Program. **Conclusion** This pioneering research not only advances the fundamental understanding of Fano resonance in ENZ media but also opens new avenues for the design and development of miniaturized and highly tunable electromagnetic devices. The ability to control dispersion through simple structural modifications in ENZ media could lead to significant improvements in the performance and efficiency of various photonic and microwave technologies, marking a crucial step towards the realization of advanced on-chip integration. **Original Publication:** "Fano Resonance in Epsilon-Near-Zero Media" *Physical Review Letters* (2023) DOI: 10.1103/PhysRevLett.133.256402 **Date of Publication:** December 24, 2024 **Contributors:** - Tsinghua University Department of Electronic Engineering - National Natural Science Foundation of China - National Key Research and Development Program **Contact:** - Editor: Li Huashan - Reviewer: Guo Ling