How to assemble InAs quantum dots
Researchers at the University of Delaware have explored novel methods for assembling indium arsenide quantum dots for use in next generation computing devices and solar energy capture.
Matthew Doty, assistant professor in the University of Delaware Department of Materials Science and Engineering, is co-author of two papers exploring novel methods for assembling quantum dots to control how electrons interact with light and magnetic fields.
Matthew Doty, a co-author of two papers exploring novel methods for assembling quantum dots to control how electrons interact with light and magnetic fields.
The papers recently appeared in Physical Review B, a journal of the American Physical Society (APS). Both papers were selected as “Editor’s Suggestions,” a designation reserved for only five percent of articles submitted to the journal.
A team led by the University of Delaware has received a Department of Energy grant to study the effects of adding wind power to the electric grid in the Mid-Atlantic region.
Doty’s group studies quantum dots, tiny semiconductors that can trap single electrons in a manner comparable to atoms like hydrogen and helium. Quantum dots are often referred to as “artificial atoms” because they have electronic properties similar to natural atoms.
Doty’s group explores the way these “artificial atoms” can be assembled to create “artificial molecules.” Unlike natural molecules, the properties of these quantum dot molecules can be tailored to create unique and tuneable properties for the electrons trapped in the molecules.
The first paper, entitled “In situ tunable g factor for a single electron conﬁned inside an InAs quantum dot molecule,” documents a new strategy for engineering the spin properties of single conﬁned electrons.
Doty’s team demonstrates this strategy by designing, fabricating and characterising a quantum dot molecule that allows the electron properties to be tuned with a small change in the voltage applied to the molecule. The success of the strategy validates a new approach to engineering optoelectronic devices with dramatically improved computational power.
The second paper, entitled “Spectroscopic signatures of many-body interactions and delocalized states in self-assembled lateral quantum dot molecules,” describes a different molecular design, in which the two quantum dots are placed side by side instead of one on top of the other. The lateral geometry changes the way in which electrons are trapped in the molecule and creates more complex electronic molecular states.
These new electronic states of the lateral molecular design provide a template for new computing architectures that overcome scaling limits of conventional charge-based computing by mediating interactions between single confined spins.
Doty’s work with quantum dot molecules is supported, in part, through funding from the National Science Foundation, which awarded him the prestigious Faculty Early Career Development Award in 2009. The highly competitive NSF Career Award is bestowed on researchers deemed most likely to become the academic leaders of the 21st century.
Doty, who joined the UD faculty in 2007, previously served as a National Research Council research associate at the Naval Research Laboratory after earning his bachelor’s degree in physics from Pennsylvania State University and his doctoral degree in physics at the University of California, Santa Barbara.