Edwin L. Aguirre
Computer technology has come a long way since ENIAC, the world’s first general-purpose electronic computer. Built in the 1940s, this behemoth used more than 17,000 vacuum tubes, weighed 27 tons and consumed 150,000 watts of power. Today’s personal computers are more powerful, compact and energy-efficient, with microprocessors operating at clock speeds in the gigahertz (billions of cycles per second) range.
Electrical and Computer Engineering Assoc. Prof. Martin Margala wants to make them perform even better. He and his research team; postdoctoral fellow Ignacio Iñiguez de la Torre, doctoral student Vikas Kaushal, master’s degree student Charu Gupta Kaushal and undergrad Kevin Rosario; are developing a unique type of super-fast chip, called the “ballistic-deflection transistor,” or BDT, which is a building block for ultrahigh-speed computers and circuits.
“Such a nanotransistor would operate a thousand times faster; in the terahertz range; and consume extremely low power and generate far less heat compared to conventional transistors,” explains Margala.
Instead of starting and stopping the flow of electrons the way standard transistors do, the BDT design uses electric fields to “steer” individual electrons and bounce them off deflectors, in a form of atomic billiards or pinball arcade game.
The layout of a BDT is described as a highway intersection, with the triangle-shaped deflector sitting in the middle of the intersection. As an electron approaches the intersection from the “south,” it passes through an electric field that causes the particle’s ballistic trajectory to shift ever so slightly. Depending on the field’s polarity, the electron can be made to hit the median so it gets diverted either to the “east” or “west.” Electrons flowing to the east would register as a one, while those flowing to the west register as a zero. This binary numeral system of ones and zeroes is used by all modern computers and digital electronic circuitry with logic gates.
(Watch an animation of how the BDT works.)
Margala’s research on BDTs actually began in 2005, when he was with the University of Rochester. Since he joined UMass Lowell in early 2007, he has continued his work in this field, receiving grants from the U.S. Air Force ($400,000), U.S. Navy ($453,000), and the Defense University Research Instrumentation Program ($60,000).
This past September, he received a $100,607 grant from the National Science Foundation (along with $40,000 from UMass Lowell) to purchase a multi-probe, wide-temperature parameter analysis system for measuring low voltages and low noises. Margala is the principal investigator in the NSF grant, with Profs. Craig Armiento and Joel Therrien serving as co-principal investigators.
“Ballistic deflection transistors should be easy to manufacture using current technologies,” says Margala. “They have the potential to revolutionize modern electronics.”