This is an electron wave quantum hologram displaying the initials “SU” of Stanford University. The yellow area is a copper surface. The holes in the copper are molecules of carbon monoxide. Constantly moving electrons on the surface of the copper bounce off the carbon monoxide molecules in predictable ways. With their dual wave/particle properties, the electron waves in the purple area create inference patterns that can store readable information, in this case, SU. To store information, the researchers arrange the molecule in specific patterns with a scanning tunneling microscope.
But in this experiment we’ve stored some 35 bits per electron to encode each letter. And we write the letters so small that the bits that comprise them are subatomic in size. So one bit per atom is no longer the limit for information density. There’s a grand new horizon below that, in the subatomic regime. Indeed, there’s even more room at the bottom than we ever imagined.“