香蕉视频

McGill researchers make important contribution to the development of quantum computing

Physicists at 香蕉视频 have developed a system for measuring the energy involved in adding electrons to semi-conductor nanocrystals, also known as quantum dots 鈥� a technology that may revolutionize computing and other areas of science. Dr. Peter Gr眉tter, McGill鈥檚 Associate Dean of Research and Graduate Education, Faculty of Science, explains that his research team has developed a cantilever force sensor that enables individual electrons to be removed and added to a quantum dot and the energy involved in the operation to be measured.

Being able to measure the energy at such infinitesimal levels is an important step in being able to develop an eventual replacement for the silicon chip in computers 鈥� the next generation of computing. Computers currently work with processors that contain transistors that are either in an on or off position 鈥� conductors and semi-conductors 鈥� while quantum computing would allow processors to work with multiple states, vastly increasing their speed while reducing their size even more.

Although the term 鈥渜uantum leap鈥� is used in everyday language to connote something very large, the word 鈥渜uantum鈥� itself actually means the smallest amount by which certain physical quantities can change. Knowledge of these energy levels enables scientists to understand and predict the electronic properties of the nanoscale systems they are developing.

鈥淲e are determining optical and electronic transport properties,鈥� Gr眉tter said. 鈥淭his is essential for the development of components that might replace silicon chips in current computers.鈥�

The electronic principles of nanosystems also determine their chemical properties, so the team鈥檚 research is relevant to making chemical processes 鈥済reener鈥� and more energy efficient. For example, this technology could be applied to lighting systems, by using nanoparticles to improving their energy efficiency. 鈥淲e expect this method to have many important applications in fundamental as well as applied research,鈥� said Lynda Cockins of McGill鈥檚 Department of Physics.

The principle of the cantilever sensor sounds relatively simple. 鈥淭he cantilever is about 0.5 mm in size (about the thickness of a thumbnail) and is essentially a simple driven, damped harmonic oscillator, mathematically equivalent to a child's swing being pushed,鈥� Gr眉tter explained. 鈥淭he signal we measure is the damping of the cantilever, the equivalent to how hard I have to push the kid on the swing so that she maintains a constant height, or what I would call the 鈥榦scillation amplitude.鈥� 鈥�

Dr. Yoichi Miyahara, Aashish Clerk and Steven D. Bennett of McGill鈥檚 Dept. of Physics, and scientists at the Institute for Microstructural Sciences of the National Research Council of Canada contributed to this research, which was published online late yesterday afternoon in the Proceedings of the National Academy of Sciences. The research received funding from the Natural Sciences and Engineering Research Council of Canada, le Fonds Qu茅b茅cois de le Recherche sur la Nature et les Technologies, the Carl Reinhardt Fellowship, and the Canadian Institute for Advanced Research.

This image shows the electrostatic energy given off when electrons are added to a quantum dot. It was created with an atomic-force microscope. Photo Credit: Dept. of Physics, 香蕉视频.