Events

Disorder-assisted transport in topological insulators and nanocrystal superlattices

May 14, 2015 at 3pm/36-428

Brian Skinner
Argonne National Laboratory

abstract:
In solid state materials, disorder is usually thought of as a hindrance to electron transport.  But when the disorder is produced by poorly-screened charged impurities, the long-ranged nature of the disorder potential can have unexpected consequences for the electrical conductivity.  In this talk I discuss two situations where the presence of charged impurities leads to an exponential increase in the conductivity.  In the first part of the talk, I show how the unexpectedly large bulk conductivity in topological insulators is the consequence of large band-bending produced by Coulomb impurities.  In the second part, I consider hopping transport in nanocrystal superlattices, and show that the presence of charged impurities leads to a universal form of the temperature-dependent conductivity.

bio:
Brian Skinner is the Eugene Wigner postdoctoral fellow at Argonne National Laboratory, where he works in the condensed matter theory group of the Materials Science Division.  Brian did his PhD at the University of Minnesota with Boris Shklovskii, where he worked primarily on electronic systems with strong Coulomb interactions.  He is joining the Center for Excitonics in the fall as a postdoctoral “theorist in residence.”