Optics using magnetic chromium sulfide bromide achieve reconfigurable negative refraction, where light bends backward, not forward

https://phys.org/news/2026-02-natural-magnetic-materials-unprecedented-ways.html

"programmable nanoscale optics bypassing need for complex, artificial metamaterials... built miniature hyperlens capable of focusing light into spots far smaller than what standard lenses allow, for high-resolution imaging... . light-bending switched on/ off using magnets or changing temperature... beyond diffraction limit high-resolution microscopes, more compact/ efficient optical data processing, advanced light manipulation for quantum computers, medical imaging: detailed non-invasive diagnostic tools"