Umklapp electron-electron scattering in bilayer graphene moiré superlattice

Abstract

Recent experimental advances have been marked by the observations of ballistic electron transport in moiré superlattices in highly aligned heterostructures of graphene and hexagonal boron nitride (hBN). Here, we predict that a high-quality graphene bilayer aligned with an hBN substrate features $T^2$-dependent resistivity caused by umklapp electron-electron (Uee) scattering from the moiré superlattice, that is, a momentum kick by Bragg scattering experienced by a pair of electrons. Substantial Uee scattering appears upon $p$-doping of the bilayer above a threshold density, which depends on the twist angle between graphene and hBN, and its contribution towards the resistivity grows rapidly with hole density until it reaches a peak value, whose amplitude changes non-monotonically with the superlattice period. We also analyse the influence of an electrostatically induced bandgap in the bilayer and trigonal warping it enhances in the electron dispersion on the electron-electron umklapp scattering.

5 pages, 3 figures, supplementary material

References in corpus (4)

• Emergence of Superlattice Dirac Points in Graphene on Hexagonal Boron Nitride
• The electronic properties of bilayer graphene
• High-temperature quantum oscillations caused by recurring Bloch states in graphene superlattices
• Wide-range $T^2$ resistivity and umklapp scattering in moiré graphene

Cited by in corpus (4)

• Higher-order Bragg gaps in the electronic band structure of bilayer graphene renormalized by recursive supermoiré potential
• High-mobility compensated semimetals, orbital magnetization, and umklapp scattering in bilayer graphene moire superlattices
• Controlling Umklapp scattering in bilayer graphene moir'e superlattice
• Hexagonal boron nitride/bilayer graphene moiré superlattices in the Dirac-material family: energy-band engineering and carrier doping by dual gating