Researchers at the UCLA Samueli School of Engineering have now shown that phonons, quantum vibrations that carry heat through a material, can travel along concentrated, ray-like paths at room temperature. “By enabling heat to be guided, focused and redistributed with nanoscale precision at room temperature, the discovery establishes a foundation for quantum thermal engineering.” At room temperature, phonons generally scatter much more often and rapidly lose their wave coherence, causing heat to spread through conventional diffusion. Boron arsenide experiences unusually weak phonon scattering, allowing wavelike heat transport to survive even at room temperature. Reference: “Phonon focusing at room temperature” by Man Li, Huan Wu, Zihao Qin, Chuanjin Su, Huu Duy Nguyen and Yongjie Hu, 23 July 2026, Nature Physics.