Event Description
Jacek Furdyna, PhD, University of Notre Dame
It is not an overstatement to say that our civilization, in one way or another, revolves around processing and storing information. This currently involves two distinct classes of materials: semiconductors for processing information, and magnetic memories for information storage. It would of course be extremely desirable to have a single material that accomplishes both functions, i.e., a material that is both semiconducting and magnetic. This is the heart of the emerging field of spin electronics (“spintronics”), the goal of which is to use both the charge and the spin of electrons to accomplish manipulation and storage of information. In this talk I will discuss our attempts toward this goal, made by achieving robust ferromagnetism in a semiconductor. As an example, I will use the well-known semiconductor GaAs, in which a fraction of the Ga ions has been replaced by magnetic Mn ions. I will discuss what makes such a structure ferromagnetic, how it is grown in the form of high-quality crystals, and what are its structural, electronic, and magnetic properties. I will then spend some time to describe various strategies which we use to manipulate the magnetic properties of this material, and will present examples of device structures which can be achieved with such a system. Finally, I will discuss the challenges that must still be surmounted to make this and similar ferromagnetic semiconductors viable for use in practical information processing. |
