A New Way to Tune the Properties of Two-Dimensional (2-D) Materials
Recent research from the labs of James Hone (mechanical engineering) and Cory Dean (physics) demonstrates a brand new method to tune the properties of two-dimensional (2-D) supplies just by adjusting the twist angle between them. The researchers constructed devices consisting of monolayer graphene encapsulated between two crystals of boron nitride and, by adjusting the relative twist angle between the layers, they had been capable of creating a number of moiré patterns.
Moiré patterns are of high interest to condensed matter physicists and supplies scientists who use them to alter or generate new digital materials properties. These patterns will be formed by aligning boron nitride (BN, an insulator) and graphene (a semimetal) crystals. When these honeycomb lattices of atoms are near alignment, they create a moiré superlattice, a nanoscale interference sample that additionally seems to be like a honeycomb. This moiré superlattice alters the quantum mechanical environment of the conducting electrons within the graphene, and due to this fact can be utilized to program significant changes within the noticed digital properties of the graphene.
To this point, most research on the results of moiré superlattices in graphene-BN systems has checked out a single interface (with both the highest or backside floor of the graphene thought of, however not each). Nonetheless, research revealed by Hone and Dean last year demonstrated that complete rotational management over one of many two interfaces was possible inside a single device.
The researchers are actually refining the power to twist monolayers of a variety of 2-D supplies to review such exotic effects as superconductivity, topologically induced ferromagnetism, and non-linear optical response in systems that lack inversion symmetry.