There has been an enormous increase in the interest to understand the nature of interface states, following the discovery of a 2-dimensional metallic state at the interface of two highly insulating oxide materials, namely LaAlO3 and SrTiO3.
Subsequent experiments have shown a large number of entirely unexpected properties associated with this 2-d system. Not only such esoteric cases, various 2-d interfacial states play crucial roles in a number of practical devices as well, including semiconductor nanomaterials with unusually high quantum efficiency for optical properties. Role of such buried interfaces can be investigated meaningfully only by a handful of techniques, with the most direct information extractable from Photoelectron spectroscopy.
I shall discuss some of the recently studied systems where the dominant property of the sample is controlled by such interfaces and present results that clarify the role of the interface in giving rise to such properties.
Specifically, I shall discuss two classes of systems, namely highly luminescent group II-VI semiconductor quantum dots and 2-dimensional heterostructures with an emphasis on LaAlO3/SrTiO3. If time permits, I shall also discuss LaTiO3/SrTiO3 heterostructures and magnetic tunnel junctions based on CoFeB/Mgo/CoFeB magnetic structures.
This will include the following two talks:
- Applications to 0-dimensional nanomaterials using medium to high energy photons; and
- Applications to 2-dimensional heterostructures with high energy photons.