First-principles electron-phonon interactions and electronic transport in large-angle twisted bilayer graphene

Twisted bilayer graphene (tBLG) has emerged as an exciting platform for novel condensed matter physics. However, electron-phonon (e-ph) interactions in tBLG and their effects on electronic transport are not completely understood. Here we show first-principles calculations of e-ph interactions and resistivity in commensurate tBLG with large twist angles of 13.2 and 21.8 degrees. These calculations overcome key technical barriers, including large unit cells of up to 76 atoms, Brillouin-zone folding of the e-ph interactions, and unstable lattice vibrations due to the AA-stacked domains. We show that e-ph interactions due to layer-breathing (LB) phonons enhance intervalley scattering in large-angle tBLG. This interaction effectively couples the two layers, which are otherwise electronically decoupled at such large twist angles. As a result, the phonon-limited resistivity in tBLG deviates from the temperature-linear trend characteristic of monolayer graphene and tBLG near the magic angle. Taken together, our work quantifies e-ph interactions and scattering mechanisms in tBLG, revealing subtle interlayer coupling effects at large twist angles.