Mapping the Density of States in Twisted Trilayer Graphene*

Twisted trilayer graphene with mirror symmetry can be created by twisting the top and bottom layers by angles of θ and - θ with respect to the center layer. This system has been extensively studied because of the robust nature of the superconducting regime and the relative ease of creating the heterostructure due to the top and bottom layers locking into angular alignment. The additional Dirac cone of the system compared to twisted bilayer graphene changes the properties of the system and gives rise to more diverse phenomena. To explore the effects of the additional third layer we map the band structure for various twist angles in several different devices. Using scanning tunneling microscopy and spectroscopy at 4.5 K we obtain local density of states maps and dI/dV curves for these devices.