Guinness World Record smashed by QR code just 50nm wide - 2500 sq nm² size is less than COVID virus

The tiny QR code was constructed using silver atoms placed by an ultra-precise scanning tunnelling microscope.
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Monash and FZU researchers build the world’s smallest QR code atom by atom

Researchers from the Monash University School of Physics and Astronomy and the Czech Academy of Sciences have created what is ...