<p>➀ Researchers discovered surface-bound excitons (quasiparticles) on the antiferromagnetic semiconductor chromium-sulfur-bromide (CrSBr), previously thought to form only within materials; </p><p>➁ The magnetic order of CrSBr enables precise control of light absorption and emission via magnetic fields, leveraging its ultrathin van der Waals crystal structure; </p><p>➂ International collaboration confirmed the reproducibility of findings, highlighting potential for technologies integrating photonics and magnetism.</p>