[PAST EVENT] Physics Colloquium

May 3, 2013
4pm - 5pm
Small Hall, Room 111
300 Ukrop Way
Williamsburg, VA 23185Map this location
The expression Coulomb drag is used to describe the mutual friction due to the Coulomb electrostatic interaction between electric currents that flow in adjacent layers of semiconductor material. This phenomenon provides a new coupling mechanism (alternative to the conventional inductance and capacitance) between spatially separated elements of nano-electronic circuitry. From a more fundamental point of view, it can be a revealing probe of novel states of electronic matter. More recently, the phenomenon of spin Coulomb drag, whereby friction occurs between currents of opposite spin orientation in a single electronic layer, has attracted attention in the context of a new branch of electronics, which is known as "spintronics". This phenomenon has been observed and quantitatively verified in experiments. Lately a new drag mechanism, based on energy rather than momentum exchange has been suggested for systems consisting of two parallel carbon monolayers (graphene). In this talk I review some of the latest theoretical and experimental developments on Coulomb drag and spin Coulomb drag in novel quantum systems such as graphene, topological insulators and cold atoms.