Graphene Reveals a Super-Rare Form of Magnetism When 3 Layers Combine Together
For something that largely exists in just two dimensions, graphene seems to be everywhere. The super-thin 'wonder material' is famous not only for its incredible strength, but also its unique, often surprising mix of thermal and electromagnetic properties.
In recent times, many of the strangest experimental discoveries in graphene research have been made when scientists stack separate layers of graphene on top of one another. When ordinary materials combine like this, nothing much happens, but even layering a few sheets of graphene together seems to produce unusual and unexpected electronic states.
Now, a new study led by researchers at Columbia University and the University of Washington has found another incidence of this kind of behaviour when graphene's one-atom-thick lattices come into contact with each other.
"We wondered what would happen if we combined graphene monolayers and bilayers into a twisted three-layer system," says Columbia University physicist Cory Dean.
"We found that varying the number of graphene layers endows these composite materials with some exciting new properties that had not been seen before."
In recent years while investigating the effects of graphene layering, scientists discovered that twisting one of the layers ever so slightly – so that the two sheets are resting at a slightly offset angle – produces what's known as a twisted 'magic angle' structure, which can alternate between being an insulator and a superconductor (either blocking electricity flowing through the material, or facilitating it with no resistance).
In the new work, Dean and his team experimented with a three-layer graphene system, constructed from ...
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