The key to making useful nanoelectronic devices from graphene is to first understand, and then be able to control, the flow of electrons through tiny snippets of the material. The absence of a bandgap in pure graphene means that although its electrical conductivity is the highest of any material bar none, it is nearly impossible to shut it off completely. Researchers at MIT and elsewhere have recently figured out not only how to build precisely defined bandgaps into composites of graphene and boron nitride, but they have also uncovered the deeper electronic structure of the material and found that it contains some of the most fascinating physics known.
What the MIT researchers basically did was take single layers of hexagonal graphene and stack them up against single layers of hexagonal boron nitride. The key is to be able to control the degree of alignment between the layers, and therefore the ease with which electrons can hop and slide from one layer to the next. In order to coax the graphene-boron honeycomb into exposing its hidden behaviors, some additional outside influence needs to be imposed. One effective way to do this is to chill everything down to within a fraction of absolute zero and add a massive, out-of-plane magnetic field.To read more, click here.