Quantum Dot Molecules: Interesting physics and opportunities for scalable quantum devices
Quantum dots are often described as artificial atoms because they have discrete energy levels analogous to those of natural atoms. Solid state quantum dots (e.g. InAs in GaAs) can be extended from artificial atoms to artificial molecules by controlling the relative spatial proximity and orientation of a pair of quantum dots. These pairs of dots are called quantum dot molecules (QDMs) because coherent tunnel coupling between the individual quantum dots leads to the formation of molecular states analogous to those in diatomic molecules. Unlike ‘natural’ molecular states, the properties of these artificial molecules can be varied both during growth and in situ by applied fields. As a result, QDMs present a unique opportunity to apply molecular engineering principles to design new components for scalable optoelectronic quantum device technologies. I will first describe how a range of spintronic and photonic properties arise from the structure, composition, and applied field environment of a QDM. I will then discuss how these properties lead to new opportunities for quantum devices. Finally, I will describe our progress toward overcoming practical challenges to create a quantum-dot-based scalable material platform for quantum device applications.
Matthew Doty earned a B.S. in physics from The Pennsylvania State University in 1998. He completed his Ph.D. in 2004 in experimental condensed-matter physics at the University of California, Santa Barbara, under the supervision of Prof. Mark Sherwin. He then spent three years as a National Research Council Research Associate at the Naval Research Laboratory, where he worked in the lab of Dr. Daniel Gammon. Prof. Doty joined the faculty of Materials Science and Engineering at the University of Delaware in 2007 where he is now Professor of Materials Science and Engineering, Physics, and Electrical and Computer Engineering. Prof. Doty’s research is focused on understanding and controlling optoelectronic processes at the quantum level for applications ranging from quantum information processing to solar energy harvesting.
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