Hector De Los Santos, a researcher with over a decade of experience in plasmon computing, has made significant strides in developing a new approach to computing that utilizes plasmons. In 2010, he was the first to put forth the radical idea of computing with plasmons. The concept started developing in his head around 2009 as he marveled at the shortcomings of traditional CMOS logic. Along with faculty from the University of South Carolina, Ohio State University, and Georgia Institute of Technology, De Los Santos then made collaborations a focus of 2024. Collectively, they came to introduce a revolutionary device that showcased the true power of plasmon-based logic.
The newly conceived Y-junction device is only five square microns in area. It can do it by controlling one plasmon with another plasmon! This exciting development is a momentous change in computing. It does so departing from current-flows based models we are used to and facing towards a new-wave flows based perspective. The promise of this technology holds the potential to change the way logic devices are manufactured and function.
De Los Santos’s work aims to address two major challenges in conventional computing: irreversibility and energy dissipation. So, he argues, what we’re doing today is simply not sustainable. Developing plasmon computing is expected to create devices that are faster, more energy efficient and more powerful.
The Birth of Plasmon Computing
De Los Santos understood the challenges of further shrinking conventional transistor technologies. This realization inspired his research into plasmon computing.
“I got the idea of plasmon computing around 2009, upon observing the direction in which the field of CMOS logic was going,” he explained. “They were following the downscaling paradigm in which, by reducing the size of transistors, you would cram more and more transistors in a certain area, and that would increase the performance.”
He pointed out that as devices miniaturize, quantum mechanical effects and leakage increases, and this exacerbates energy dissipation. So this got him to look for other ways of computing.
“I began to think, ‘How can we solve this problem of improving the performance of logic devices while using the same fabrication techniques employed for CMOS—that is, while exploiting the current infrastructure?’” De Los Santos said. “I came across an old logic paradigm called fluidic logic, which uses fluids… So I had the idea, why don’t we implement a paradigm analogous to that one, but instead of using air as a fluid, we use localized electron charge density waves—plasmons.”
The Y-Junction Device
In 2024, De Los Santos and his team got a big winner. They went on to create, impressively, a Y-junction device which is fundamental to plasmonic-based logic. The device operates by imposing a direct current (DC) voltage between the metal of the Y-junction and an adjacent ground plane. This leaves the device awash in a ether of static electrons.
This arrangement makes it possible to direct a plasmon off to one side. The control plasmon interacts with an incoming bias plasmon, thus steering it down one leg of the Y-junction. The resulting disturbance is quite important. That disturbance doubles their voltage on that leg.
“This device demonstrates the interaction of two plasmons,” De Los Santos remarked. “The next step would be to demonstrate and fabricate the full device, which would have the two controls.”
The implications for this technology reach well beyond its intended use. By tapping into the power of plasmons, De Los Santos sees a future where energy isn’t wasted as heat, and computers operate at lightning-fast speeds. He asserts that “Going back to the analogy of throwing a pebble on the pond: It takes very, very low energy to create this kind of disturbance.”
Challenges Ahead
Even with all of the exciting advancements found in plasmon computing, De Los Santos is quick to recognize that a long road lies ahead. His most poignant observation is the gulf between our current knowledge structures and the cross-disciplinary nature of his work.
The hardest part, though, is that the technology doesn’t match up with logic devices made today. These devices only work on FLOWS of current, and herein lies the rub. He stated, “This is based on wave flows. People are used to everything else, and it’s intimidating to think about learning such a serious looking device.”
The most important hurdle is just building a robust knowledge base. It takes advanced knowledge across complementary disciplines including metal-oxide-semiconductor physics, electromagnetic waves and quantum field theory.
Convincing people to fund the work and make sense of it is another hurdle, he added. There’s not really a fabrication limitation.