University of Illinois, Urbana-Champaign
"For contributions to the fundamental understanding of excitonic matter and ballistic phonons in semiconductors, made possible by pioneering development of graphic imaging techniques."
Wolfe is a professor of physics at the University of Illinois at Urbana-Champaign and a member of the Frederick Seitz Materials Research Laboratory. He received his Bachelors degree in 1965 and his Ph.D. in 1972, both in physics from the University of California at Berkeley. His thesis work involved dynamic nuclear polarization, magnetic resonance, and optical pumping in solids. As a postdoc in Jeffries group, he and co-workers studied excitons in semiconductors and obtained the first photograph of an electron-hole droplet. He joined the Physics Department at Illinois in 1976.
Wolfes group at Illinois figured out how to image diffuse clouds of electron-hole droplets and discovered striking anisotropies in droplet transport due to a phonon wind. Using optically calibrated strain gradients they measured mobilities of droplets and excitons, they extracted thermodynamic properties of excitonic matter employing strain-confinement techniques, and they developed time-resolved-imaging methods to characterize the transport of photoexcited carriers in bulk crystals and quantum wells. His group also devised a method to image ballistic phonons directly. Phonon imaging has since provided graphic insights into such topics as phonon focusing, lattice dynamics and ultrasound propagation. The method has been used to study the scattering of phonons from electrons, interfaces, superlattices, and defects as described in Wolfes book entitled Phonon Imaging (Cambridge, 1998).
Wolfe is a Fellow in the American Physical Society. He has directed multi-investigator research grants for the National Science Foundation (1991-95) and the Department of Energy (1989-91) at the Frederick Seitz Materials Research Laboratory. He received a Senior Scientist Award of the Alexander von Humboldt Foundation in 1989 and a JSPS Fellowship in Japan in 1991. Between 1999 and 2002 he served as Associate Head for Graduate Studies in Physics at Illinois.