Condensed Matter Seminar Series
Electron Transport in Correlated Nanostructures
Khaled A. Al-Hassanieh
University of Tennessee, Oak Ridge National Laboratory, and Florida State University
Monday February 26, 10:45 am, Room 246 (HEP conference room)
There has been a rapidly increasing interest in studying systems
on the nanometer scale in the past decade. The importance of such
systems cannot be overstated both from the basic research and applied
points of view. Due to their small sizes and confined nature, the
electronic correlations are dominant. This has been manifested in
the observation of several effects such as the Kondo effect in quantum
dots (QDs), molecular transistors, and other nanosystems. I will
first present a brief overview of correlation effects in
nanosystems. Then I will discuss the results of some of our
recent numerical simulations. In the first study , we
investigated the transport properties of coupled double-level
QDs. We observed the formation of a novel ferromagnetic phase in
the quarter filling regime. This phase represents a QD
realization of the double exchange mechanism. In a second study
, we reproduced numerically the results of an important experiment
involving two QDs coupled through an open region . The
experimental results indicate the mesoscopic realization of RKKY
interaction. Our results, on the other hand indicate the
possibility of Fano antiresonance. Finally, I will introduce a
new procedure to study nanotransport using the recently developed
adaptive time-dependent density-matrix renormalization group .
 G. B. Martins et al., Phys. Rev. Lett. 94, 026804 (2005).
 G. B. Martins et al., Phys. Rev. Lett. 96, 066802 (2006).
 N. J. Craig et al., Science 304, 565 (2004).
 K. A. Al-Hassanieh et al., Phys. Rev. B 73, 195304 (2006).
Host: Harold Baranger