Anomalous electron-phonon coupling in magic-angle twisted bilayer graphene.*

We investigate the electron-phonon coupling properties of magic-angle twisted bilayer graphene (MATBG) using gate-dependent Raman spectroscopy. We use illumination from the bellow and ion-gate to dope MATBG highly. Thus, we monitor the electron-phonon coupling through the C-C stretching mode (G band) linewidth as a function of gate voltage. We then compare the MATBG results with large-angle twisted bilayer graphene and Bernal bilayer. We support our results with an atomistic model that reveals a unique MATBG electron-phonon coupling signature influenced by its singular electronic and solitonic structures. Our results point to a relationship between electron-phonon

coupling and the strongly correlated phenomena in MATBG.