Podcast Episode
Researchers at the Regensburg Center for Ultrafast Nanoscopy in Germany and the University of Birmingham in the UK have now shattered that barrier. Their technique, published in Nano Letters on 30 January 2026, achieves resolution at 0.1 nanometresÔÇöapproximately the size of a single atom.
Initially, this approach achieved resolution around ten nanometresÔÇöimpressive, but still about thirty times too coarse for atomic-scale features. The breakthrough came when the team moved the tip even closer and observed something unexpected.
The explanation lies in quantum tunneling. Although the tip and surface never physically touch, electrons can still jump between them through the quantum mechanical process of tunneling. The oscillating electric field of the infrared light forces electrons to move back and forth, producing a detectable electromagnetic signal the researchers call near-field optical tunneling emission, or NOTE.
Scientists Break Century-Old Microscopy Barrier to See Individual Atoms with Light
January 31, 2026
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Researchers from Germany and the UK have achieved what was thought impossible for over a century: using visible light to see individual atoms. By exploiting quantum tunneling effects, they've pushed optical microscopy to resolutions nearly one hundred thousand times smaller than conventional limits allow.
Breaking the Diffraction Limit
For more than a century, physicists accepted that optical microscopes could never see individual atoms. The reason was fundamental: light cannot be focused more sharply than its own wavelength, a constraint known as the diffraction limit. Since visible light has wavelengths hundreds of times larger than atoms, seeing atomic-scale features with optical microscopy seemed forever out of reach.Researchers at the Regensburg Center for Ultrafast Nanoscopy in Germany and the University of Birmingham in the UK have now shattered that barrier. Their technique, published in Nano Letters on 30 January 2026, achieves resolution at 0.1 nanometresÔÇöapproximately the size of a single atom.
How It Works
The method uses an extremely sharp metal tip positioned extraordinarily close to a material's surface, with a gap smaller than a single atom separating them. When researchers illuminate this setup with a continuous-wave mid-infrared laser, the light becomes concentrated at the tip's apex.Initially, this approach achieved resolution around ten nanometresÔÇöimpressive, but still about thirty times too coarse for atomic-scale features. The breakthrough came when the team moved the tip even closer and observed something unexpected.
The Quantum Tunnel
"At very small distances, the signal shot up dramatically," said Felix Schiegl from the University of Regensburg. "We didn't immediately understand what was happening. The real surprise came when we realised we were resolving atomic-scale features."The explanation lies in quantum tunneling. Although the tip and surface never physically touch, electrons can still jump between them through the quantum mechanical process of tunneling. The oscillating electric field of the infrared light forces electrons to move back and forth, producing a detectable electromagnetic signal the researchers call near-field optical tunneling emission, or NOTE.
Practical Implications
Unlike previous atomic-resolution techniques requiring expensive ultrafast laser systems, this method works with standard continuous-wave lasers, potentially making it accessible to laboratories worldwide. The approach could enable scientists to study light-matter interactions at the scale of individual atoms, offering insights into how microscopic processes determine the properties of semiconductors, quantum devices, and advanced materials.Published January 31, 2026 at 6:56pm
