Charles A. Reynolds Distinguished Lecture Series
Correlated Electrons in a Designer Semiconductor Nanostructure
Center for Probing the Nanoscale
Some of the most intriguing problems in solid state physics arise when the motion of one electron dramatically affects the motion of surrounding electrons. Traditionally, such highly-correlated electron systems have been studied mainly in materials with complex transition metal chemistry. Over the past decade, researchers have learned to confine one or a few electrons within a nanoscale semiconductor "artificial atom", and to understand and control this simple system in exquisite detail. I will discuss how we can combine such individually well-understood components to create a novel highly-correlated electron system within a nano-engineered semiconductor structure [1,2]. We tune the system in situ through a quantum phase transition between two distinct states, each a version of the Kondo state in which a bound electron interacts with surrounding mobile electrons. The boundary between these competing Kondo states is a quantum critical point: the exotic and previously elusive two-channel Kondo state, in which electrons in two reservoirs are entangled through their interaction with a single localized spin.
Wednesday, April 18, 2007
Gant Science Complex