Center for Excitonics Seminar Series Announcement The Center for Excitonics is an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science and Office of Basic Energy Sciences The Center for Excitonics invites you to join us at the next seminar of the Spring 2010 series. Please forward this information on to others who might be interested in attending this and other center seminars. Title: State-Resolved Exciton Dynamics in Quantum Dots Presenter: Patanjali Kambhampati Organization: Department of Chemistry, McGill University Date: April 15, 2010 Time: 3:00 - 4:00pm Place: 34-401A (Grier A) Center URL: www.rle.mit.edu/excitonics Seminar URL: www.rle.mit.edu/excitonics/patanjali-041510.html Abstract The semiconductor quantum dot is one of the canonical systems in nanoscience. Whereas the nanometer size of these materials is obvious, the richer and more meaningful issue is the presence of quantum confinement effects conferred by virtue of size. One may qualitatively describe quantum dot electronic structure like the textbook particle in a sphere. However, this simple picture misses the vast majority of the processes which ultimately control the functionality of the quantum dot. Our goal is to obtain a detailed picture of the rich inner workings of the quantum dot. We introduce a mixed time/frequency domain ultrafast spectroscopic approach which we denote State-Resolved Exciton Dynamics. We have applied this approach to resolve several long standing issues central to quantum dot science: 1) Hot exciton relaxation dynamics: radiationless transitions on the nanoscale 2) Optical gain: recovering predictions from theory and revealing new physics 3) Electronic structure of multiexcitons: creation of an artificial periodic table 4) electron-phonon interactions: quantizing piezoelectricity The power of this approach is reflected by our ability to predict aspects of unrelated experiments, e.g. single dot blinking and multiple exciton generation. In addition to the basic science of excitons in nanoscale materials, these fundamental results have advanced the design principles for a broad range of applications including: LEDs, lasers, solar cells, THz radiation sources, piezoelectrics, and non-classical light. Bio Patanjali Kambhampati received a B.A. in Chemistry from Carleton College in 1992, and a Ph.D. in Chemistry from the University of Texas at Austin in 1998. His doctoral work focused on ultra-high vacuum surface studies of adsorbate-substrate charge transfer excitations and surface enhanced Raman scattering under the supervision of Alan Campion. From 1999 – 2001 he was a Postdoctoral Associate with Paul Barbara, also at the University of Texas at Austin. His postdoctoral work focused on femtosecond laser spectroscopy of condensed phase chemical dynamics of the solvated electron and intramolecular electron transfer. From 2001 – 2003 he was involved in early phase work in a fiber optic startup based in Los Angeles. At McGill University, where his group focuses on ultrafast dynamics in quantum dots, he was an Assistant Professor from 2003 – 2009 and is presently an Associate Professor.