Duncan Steel

Professor Steel researches quantum optics in condensed matter physics: the interaction of light with condensed matter is an extremely complex and rich field of physics. The interest in direct bandgap semiconductors for potential applications in quantum optoelectronics has shown that current understanding of these systems is very poor. The interaction of light with these materials is an intrinsic many-body problem, but the effects of disorder greatly complicate the description of these systems and create the opportunity for observing new optical phenomena such as super radiance, photon echoes, and Rabi flopping from excitons. Professor Steel’s condensed matter group is now focusing on the study of quantum dots and nanostructures with experiments aimed at problems in quantum computing. These systems are particularly important as nanofabrication technology develops. Recent work has demonstrated optically induced and detected quantum entanglement in a single quantum dot. Efforts are now underway to demonstrate coherent optical control of spins and demonstration of a simple quantum algorithm.

Professor Steel’s research in biophysics: focuses on developing and applying optical and laser based methodologies, especially single molecule spectroscopy, to the study of the second half of the genetic code. The first part of the genetic code relates to structure and information stored in DNA, specifically, the DNA codes for the amino acid sequence of proteins, the affecters of all biological function. However, proteins are complex three-dimensional structures whose structure and function are uniquely related to the linear amino acid sequence. Understanding this structure, and the mechanisms by which a linear amino acid chain collapses into a functional three-dimensional protein, is the emphasis of this program. Experimental work includes the development and application of fast laser spectroscopy methods for studies of structure. One of the more recent startling discoveries shows that contrary to the historical dogma, refolding proteins attain full biological function without returning to the so-called native state, a discovery made possible by this group’s development of ultra sensitive laser spectroscopy techniques. Most recently, they are using their custom designed single molecule microscopes to study aging induced changes in control and regulation of DNA for protein transcription.

Professor Steel is a Guggenheim Scholar and a Fellow of the American Physical Society, Optical Society of America, and the IEEE.

Selected Publications

Distinct classes of amyloid pores formed by Ab40 on lipid bilayers determined by simultaneous single molecule fluorescence and conductivity measurements, (J. Schauerte, Pam Wong, Kathleen Wisser, Duncan Steel, Ari Gafni), (2007).

Application of Single Molecule Spectroscopy to the Study of Oligomers of Amyloidogenic Proteins, (Hao Ding, Pamela T. Wong, Edgar L. Lee, Ari Gafni, and Duncan G. Steel), submitted,Biophysical Journal, (2007).

Coherent optical spectroscopy of a strongly driven quantum dot, (Xiaodong Xu, Bo Sun, Paul R. Berman, Duncan G. Steel, Allan Bracker, Dan Gammon, Lu J. Sham), Science 317, 929-932 (2007).

Fast Spin State Initialization in a Singly-Charged Quantum Dot, (Xiaodong Xu, Yanwen Wu, Bo Sun, Qiong Huang, Jun Cheng, D.G. Steel, A. S. Bracker, D. Gammon, and C. Emary, L. J. Sham), Physical Review Letters 99, 097401 (2007).

Selective Optical Control of Electron Spin Coherence in Singly Charged Quantum Dots via Oscillating Dark and Bright States, (Yanwen Wu, Erik D. Kim, Xiaodong Xu, Jun Cheng, D. G. Steel A. S. Bracker, D. Gammon, Sophia Economou, and L. J. Sham), Physical Review Letters 99, 097402 (2007).

Single-Molecule Kinetics Reveals New Signatures of Half-sites Reactivity in Dihydroorotate Dehydrogenase A Catalysis, (Jue Shi, Joe Dertouzos, Ari Gafni, Duncan Steel, Bruce A. Palfey),Proc. National Academy of Sciences, USA 103, 5775-5780 (2006).

Simulated Data Sets for Single Molecule Kinetics: Some Limitations and Complications of Data Analysis, (Jue Shi, Ari Gafni, and Duncan Steel), European Biophysics Journal with Biophysics Letters 35, 633-645 (2006).

Density Matrix Tomography through Coherent Optical Rotation of an Exciton Qubit in a Single Quantum Dot , (Yanwen Wu, Xiaoqin Li,. L. M. Duan, and D. G. Steel, D. Gammon, Lu Sham),Phys. Rev. Lett. 96, 087402 (2006).

Conformational Dynamics of the Isoalloxazine Ring in Substrate-free PHBH: Single Molecule Studies, (Jeffrey R. Brender, Joe Dertouzos, David P. Ballou, Vincent Massey, Bruce A. Palfey, Barrie Entsch Ari Gafni, and Duncan Steel), JACS 27, 18171-18178 (2005).

For a list of Gafni/Steel publications, click here. 

Field(s) of Study

• Optical Physics in Condensed Matter and Biomolecules