Editor’s perspective: The University of Arizona stands on the verge of pioneering the first petahertz-speed transistor globally. If this research succeeds, it could herald a groundbreaking era in computing, where innovation is governed by the speed of light instead of electricity.
A team of researchers has revealed a significant breakthrough that may one day allow computers to function millions of times quicker than the most advanced processors available today.
Led by scientists at the University of Arizona alongside international collaborators, this discovery focuses on utilizing ultrafast light pulses to manage electron movement in graphene, a one-atom-thick material.
Recently published in Nature Communications, the study shows that firing laser pulses of less than a trillionth of a second at graphene enables electrons to bypass barriers almost instantaneously. This phenomenon, termed quantum tunneling, has long fascinated physicists, and the team’s ability to manipulate it in real time is a major milestone.
Mohammed Hassan, an associate professor of physics and optical sciences at the University of Arizona, noted that this advancement could lead to processing speeds in the petahertz range—over a thousand times faster than current computer chips. Such a progression, he emphasized, would revolutionize computing across various domains, including artificial intelligence, space exploration, chemistry, and healthcare.
Hassan, who previously spearheaded the world’s fastest electron microscope, collaborated with colleagues from the University of Arizona, Caltech’s Jet Propulsion Laboratory, and Ludwig Maximilian University of Munich. Their initial research examined graphene’s electrical conductivity when exposed to laser light. Ordinarily, the symmetrical nature of graphene causes currents on either side to cancel each other out, resulting in zero net current.
However, after modifying the graphene samples, the team made an unexpected discovery. They noted that a single electron could “tunnel” through the material, a fleeting occurrence they could capture in real time. This surprising finding spurred further exploration, ultimately leading to the development of what Hassan refers to as “the world’s fastest petahertz quantum transistor.”
To realize this, the researchers used a commercially available graphene phototransistor, enhanced with a unique silicon layer. They subjected it to a laser that toggled on and off at a remarkable rate of 638 attoseconds—each attosecond equating to one quintillionth of a second. The outcome was a transistor capable of operating at petahertz speeds, an achievement once thought unattainable.
Distinct from many scientific advancements that require meticulously controlled lab conditions, this new transistor operates under normal, ambient conditions. This breakthrough could facilitate the technology’s adaptation for commercial applications and integration into the next generations of electronic devices.
Hassan and his team are currently collaborating with Tech Launch Arizona to patent and commercialize their innovation. Their upcoming goal is to create a version of the transistor that works with standard, commercially available lasers, thereby enhancing accessibility for industry partners.