Cloning of Dirac fermions in graphene superlattices

Understand

Lateral superlattices have attracted major interest as this may allow one to modify spectra of two dimensional electron systems and, ultimately, create materials with tailored electronic properties.

• Previously, it proved difficult to realize superlattices with sufficiently short periodicity and weak disorder, and most of the observed features could be explained in terms of commensurate cyclotron orbits.
• Evidence for the formation of superlattice minibands (so called Hofstadter's butterfly) has been limited to the observation of new low-field oscillations and an internal structure within Landau levels.
• Here we report transport properties of graphene placed on a boron nitride substrate and accurately aligned along its crystallographic directions.