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by krono
2011 days ago
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Any graphene research in particular that you're personally excited about? Past/ongoing/future, theoretical/practical, anything! The graphene news that I as a non-academic get exposed to, and that is in a form that I can understand (i.e. not highly technical papers), is mostly limited to sensationalist battery improvement articles. A real shame, as so much seems to be going on behind the scenes! |
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https://en.wikipedia.org/wiki/Hofstadter%27s_butterfly
In the '70s, Hofstadter wrote about this neat fractal pattern that would show up in the band structure of a material in a sufficiently large magnetic field. Specifically, the magnetic field strength times the crystal unit cell area needed to be big. Magnetic field strength is limited by how much current you can put around a superconducting solenoid. Unit cell area is generally something that you can't change for ordinary crystals: it's just set by the chemistry of the material.
Back in 2012-ish, a few groups managed to artificially increase the area of the unit cell by multiple orders of magnitude by aligning the graphene with hexagonal boron nitride, which has the same crystal structure and a very similar size. When aligned, the moire pattern itself has a large size, and that was enough to see the butterfly.