In 2024, Hector De Los Santos, then the University of South Carolina, Ohio State University and later the Georgia Institute of Technology researcher, made significant strides toward plasmonic computing becoming a reality. His work is truly leading to next-generation technologies in this space. In 2010, De Los Santos pitched a radical concept that computing should be done with plasmons. The inspiration came from this fast moving world of the time, which is CMOS logic. He recently developed a pioneering Y-junction device. This ambitious new creation masterfully illustrates the basic concepts of plasmonics logic.
De Los Santos’s journey started back in 2009 when he first saw the potential of going beyond classic CMOS technology. He found that the smaller transistors become in their quest for ever-higher performance, the more they begin to suffer from the effects of quantum mechanics. Furthermore, power dissipation is a major issue. He dreamed of something much bigger – an entirely new paradigm. In this new model, plasmons — quantum particles of light that can transmit information — might be manipulated for new, advanced forms of computing.
A tiny Y-junction device, the size of about five square microns, acts as a key building block of this new technology. In this setup, De Los Santos would apply a direct current (DC) voltage between the Y’s metal superstructure and a ground plane. Unfortunately, this action created a virtual, static sea of electrons. This structure allows quick, low-energy perturbations to travel at velocities outpacing traditional particles. It demonstrates a better, more efficient alternative to today’s energy-hogging technologies.
The Mechanics of Plasmon Computing
At the core of De Los Santos’s device is its ability to control one plasmon with another. The Y-junction device functions using the ability to launch a bias plasmon at the base of the Y shape. Once this plasmon reaches the junction, it usually divides into two channels. De Los Santos, for his part, adds a control plasmon along a wire that’s cut at an angle to the incoming wire. This clever arrangement let him reroute the bias plasmon down one leg of the Y.
“Now, imagine that at the Y junction you apply another wire at an angle to the incoming wire. Along that new wire, you send another plasmon, called a control plasmon. You can use the control plasmon to redirect the original bias plasmon into one leg of the Y.” – Hector De Los Santos
This redirection, in turn, enables the tool to generate digital output, which can stand in for binary 0s and 1s. It gives a powerful tool to process information with very low energy consumption and fast computational speeds.
De Los Santos elaborates on the energy efficiency of plasmon computing:
“It takes very, very low energy to create this kind of disturbance. The energy to excite a plasmon is on the order of attoJoules or less. And the disturbance that you generate propagates very fast.”
The natural speed and efficiency of plasmons could solve some of the major issues plaguing today’s conventional computing approaches.
Challenges Ahead for Plasmon Technology
Though the promise of plasmon-based computing is exciting, De Los Santos is the first to recognize the hurdles that still remain. This innovative technology’s biggest obstacle is ahead. It’s misaligned with the burgeoning logic device paradigms that focus on current flows. Instead, it’s based on wave flows. This deep and transformative change can create additional confusion and resistance from those used to more conventional methods.
“I think the main challenge is that the technology doesn’t follow from today’s paradigm of logic devices based on current flows. This is based on wave flows.” – Hector De Los Santos
Additionally, De Los Santos argues that the interdisciplinary approach needed to fully understand these concepts can be an added barrier. The science behind the interaction between metal-oxide-semiconductor physics, electromagnetic waves, and quantum adjacent field theory is difficult enough unto itself. It is seldom found in one person.
“The knowledge base to understand the device rarely exists in a single head.” – Hector De Los Santos
These challenges are enough to make anyone pessimistic, but he chooses optimism in looking ahead at future applications of this technology. His next steps – in collaboration with other members of HZB’s professorial matrix – are to add control plasmons on either side of the junction to further enhance functionality.
Future Directions and Implications
De Los Santos envisions making bigger and more elaborate structures. Rather than letting plasmon research languish in a lab, by building a full adder — a fundamental building block in computing — he hopes to create pathways for real-world usage. That’s his hope, anyway, that by taking this radically different approach more efficient and powerful computing systems would arise. These systems will push past the limits of today’s technology.
“I demonstrated the partial device, that is just the interaction of two plasmons. The next step would be to demonstrate and fabricate the full device.” – Hector De Los Santos
If done right, it has the potential to fundamentally change how we process and store information. It would reduce energy use and increase speed compared to the process done today.