Condensed Matter Seminars

Combining scanning probe microscopy with electrical transport measurements is a powerful approach to probe low-dimensional systems. The local information provided by scanning probe microscopy is invaluable for studying effects such as electron-electron interactions and scattering. Using this approach, we have probed the local electronic properties of mono- and bilayer graphene with atomic resolution. We studied the effect of ripples, charged impurities and defects on the local density of states. We find that long-range scattering from ripples and impurities shifts the Dirac point leading to electron and hole puddles. Short-range scattering from lattice defects mixes the two sublattices of graphene and tends to be strongly suppressed away from the Fermi energy. In addition, in bilayer graphene we observe an opening of a band gap due to the application of a transverse electric field.