Robust zero-averaged wave-number gap inside gapped graphene superlattices

On the number of gapped repeats with arbitrary gap

For any functions f(x), g(x) from N to R we call repeats uvu such that g(|u|) ≤ |v| ≤ f(|u|) as f, g-gapped repeats. We study the possible number of f, g-gapped repeats in words of fixed length n. For quite weak conditions on f(x), g(x) we obtain an upper bound on this number which is linear to n.

Double hole cyclotron resonance in zero-gap HgTe-CdTe superlattices.

Electron interactions and gap opening in graphene superlattices.

We develop a theory of interaction effects in graphene superlattices, where tunable superlattice periodicity can be used as a knob to control the gap at the Dirac point. Applied to graphene on hexa-boron-nitride (G/h-BN), our theory predicts substantial many-body enhancement of this gap. Tunable by the moiré superlattice periodicity, a few orders of magnitude enhancement is reachable under opti...

Energy gap of Kronig-Penney-type hydrogenated graphene superlattices

The electronic structure of graphene-graphane superlattices with armchair interfaces is investigated with first-principles density-functional theory. By separately varying the widths, we find that the energy gap Eg is inversely proportional to the width of the graphene strip and that the gap increases as the hydrogenated strip becomes wider due to the enhanced confinement effect. It is further ...

Twisting bilayer graphene superlattices.

Bilayer graphene is an intriguing material in that its electronic structure can be altered by changing the stacking order or the relative twist angle, yielding a new class of low-dimensional carbon system. Twisted bilayer graphene can be obtained by (i) thermal decomposition of SiC; (ii) chemical vapor deposition (CVD) on metal catalysts; (iii) folding graphene; or (iv) stacking graphene layers...