Physics Department Master's Defense, "Extraordinary Magnetoresistance in Two and Three Dimensions: Geometrical Optimization ," by Lisa Pugsley, WPI Graduate Student
Science / Technology - Colloquium
Wednesday, April 25, 2012
1:00 PM-2:00 PM
The extraordinary magnetoresistance (EMR) in metal-semiconductor
hybrid structures was first demonstrated using a van der Pauw
configuration for a circular semiconductor wafer with a concentric
metallic inclusion in it. This effect depends on the orbital motion
of carriers in an external magnetic field, and the remarkably high
magnetoresistance response observed suggests that the geometry of
the metallic inclusion can be optimized to significantly enhance the
EMR. Here we consider the theory and simulations to achieve this
goal by comparing both two-dimensional as well as three-dimensional
structures in an external magnetic field to evaluate the EMR in them.
For a 10 micron 2D square structure with a square metallic inclusion,
we see a MR up to 10^7 percent for an applied magnetic field of 1 Tesla.
Calculations for the three dimensional structure are in progress.
Sponsored by: WPI Physics Department
Suggested Audiences: College
Last Modified: April 12, 2012 at 2:22 PM