Imagine computers operating a million times faster than today’s most advanced processors.
This futuristic vision is one step closer to reality, thanks to an international team of scientists, including researchers from the University of Arizona, who have successfully demonstrated the world’s first petahertz-speed phototransistor capable of functioning under ambient conditions.
The research, published in Nature Communications, details a revolutionary method of manipulating electrons in graphene using ultrafast pulses of light, each lasting less than a trillionth of a second.
This monumental achievement harnesses a quantum effect known as tunneling, where electrons bypass physical barriers almost instantaneously, pushing the theoretical limits of computer processing power.
“We have experienced a huge leap forward in the development of technologies like artificial intelligence software, but the speed of hardware development does not move as quickly,” said Mohammed Hassan, an associate professor of physics and optical sciences at the University of Arizona, who has long championed light-based computer technology.
“By leaning on the discovery of quantum computers, we can develop hardware that matches the current revolution in information technology software. Ultrafast computers will greatly assist discoveries in space research, chemistry, health care and more.”
The team, comprising UA colleagues Nikolay Golubev (assistant professor of physics), Mohamed Sennary (graduate student, optics and physics), Jalil Shah (postdoctoral scholar of physics), and Mingrui Yuan (optics graduate student), collaborated with researchers from the California Institute of Technology’s Jet Propulsion Laboratory and the Ludwig Maximilian University of Munich in Germany.
The serendipitous discovery emerged from their initial study of graphene’s electrical conductivity.
When a laser illuminates graphene, the excited electrons typically generate equal and opposite currents that cancel each other out due to the material’s symmetrical atomic structure.
However, by modifying commercially available graphene phototransistors with a specialized silicon layer, the researchers observed an unexpected phenomenon: a single electron effectively “tunneling” through the graphene almost instantaneously.
“That is what I love most about science: The real discovery comes from the things you don’t expect to happen,” Hassan said.
“Once we realized that we had achieved this tunneling effect, we had to find out more.”
Utilizing a laser that switches on and off at an astounding rate of 638 attoseconds (one-quintillionth of a second), the team created what Hassan describes as “the world’s fastest petahertz quantum transistor.”
This breakthrough is particularly significant because, unlike many scientific advancements that require stringent conditions, this new transistor performs optimally in ambient environments, paving the way for its potential commercialization and integration into everyday electronics.
Hassan is currently working with Tech Launch Arizona, the university’s technology commercialization arm, to patent and market this innovative technology.
While the initial prototype used a specialized laser, the researchers are actively working on developing a transistor compatible with commercially available equipment, aiming for widespread adoption.
“The University of Arizona is already known for the world’s fastest electron microscope, and we would also like to be known for the first petahertz-speed transistor,” Hassan added, anticipating a new era of computational power that could redefine our technological landscape.
