Condensed Matter Physics Seminar

Dr Romain Danneau, Karlsruhe Institute of technology, Germany

Friday 27 February 2015, 1500-1600
C1 Physics Building

Quantum transport in bilayer graphene-boron nitride van der Waals heterostructures

When graphene is placed on an atomically flat substrate its charge carrier mobility dramatically increases and therefore its intrinsic properties can be eventually explored. By pilling up two-dimensional materials one can design artificial heterostructures which are maintained by van der Waals forces. The case of graphene on hexagonal boron nitride is a striking example. In these systems, conductivity is strongly temperature dependent and charge carrier mobility has been measured up to two orders of magnitude higher than usual graphene on SiO2. We will present some electronic transport experiments where bilayer graphene are sandwiched between two boron nitride multiayers. We studied the effect of a displacement field on the proximity induced superconductivity in these systems as well as the effect of a potential barrier on the charge carriers. We will show that the fully encapsulated graphene devices connected solely from the edge provide the best quality devices.

The figure shows data representing a large scale Fraunhofer pattern in a graphene bilayer connected from the edge with Al contact.