Commensurate-incommensurate transition for graphene on hexagonal boron nitride

Understand

When a crystal is subjected to a periodic potential, under certain circumstances (such as when the period of the potential is close to the crystal periodicity; the potential is strong enough, etc.) it might adjust itself to follow the periodicity of the potential, resulting in a, so called, commensurate state.

• Such commensurate-incommensurate transitions are ubiquitous phenomena in many areas of condensed matter physics: from magnetism and dislocations in crystals, to vortices in superconductors, and atomic layers adsorbed on a crystalline surface.
• Of particular interest might be the properties of topological defects between the two commensurate phases: solitons, domain walls, and dislocation walls.
• Here we report a commensurate-incommensurate transition for graphene on top of hexagonal boron nitride (hBN).