New studies expand our view of what constitutes a “computer” and how small a computing unit can be.
If we define a “computer” as any device that processes information through input and output, the question arises as to what objects can perform these calculations and how small these computers can be. As transistors reach the limits of miniaturization, finding answers to these questions becomes crucial as they could lead to the development of a new computing paradigm.
In a new study published in EPJ Plus by researchers at Tulane University in New Orleans, Louisiana, Gerard McCaul and his team show that atoms, one of the most basic building blocks of matter, can serve as a reservoir for computers to use where all inputs and outputs take place Processing is visual.
“We had the idea that computational capacity is a universal property shared by all physical systems, but within that paradigm there is a great wealth of framework for how one would actually attempt to perform computation,” says McCaul.
He adds that one of the most important of these frameworks is neuromorphic, or reservoir, computing with a neuromorphic computer that aims to mimic the brain. This concept underpins the explosive development of machine learning and AI over the past few decades, resulting in a potentially nonlinear computer where the output is not linearly proportional to the input. This is desirable as it could lead to a computer architecture that is flexible enough that any given output can be achieved given an appropriate input.
“This means that if we want a certain calculation result, we are guaranteed that there is an input to the calculation that will achieve it,” says McCaul. “That won’t work if our system only reacts linearly!”
The team proposed a single-atom nonlinear computer in which input information is directly encoded in light and the output is also in the form of light. The calculation is then determined by filters through which the light output is passed.
“Our research confirmed that this approach works in principle and validated the fact that the system performed better when the input light was designed to induce a higher degree of nonlinearity in the system,” says McCaul. “I would probably argue that with this work we are trying to emphasize that the minimal computational system really exists at the level of a single atom, and that computations can be performed solely using optical processes.”
Reference: “Towards Single Atom Computing via High Harmonic Generation” by Gerard McCaul, Kurt Jacobs and Denys I. Bondar, 5 February 2023, The European Physical Journal Plus.