Complex scientific models can be simulated on the computer, and large data volumes such as editing video material require a lot of computing power and time. Researchers from the Chair of Laser Physics at Friedrich-Alexander-Universitat Erlangen-Nurnberg (FAU) and a team from the University of Rochester in New York have demonstrated how the speed of fundamental computing operations could be increased in the future to up to a million times faster using laser pulses. The journal Nature published their findings on May 11, 2022.
Field-effect transistors are responsible for the computing speed of smartphones and computers today. To produce faster devices, transistors are constantly reduced in size to make them fit onto chips as many as possible. Modern computers can run at a staggering speed of several gigahertz. This translates into several billion computing operations per second. The smallest transistors are 5 nanometers (5.00005 millimeters), which is less than one atom. There are limits on how small chip manufacturers can go. At a certain point it will not be possible to make transistors smaller.
Light is quicker
Physics researchers are trying to control electronics using light waves. One femtosecond is the time it takes to oscillate a light wave. This is one-millionth one billionth of a second. The goal of petahertz signal processing, or light wave electronics, is to control electrical signals using light. This could make computers of the future more efficient than ever before.
From light waves to current pulses
Electronics can be used to transmit and process data and signals using binary logic (1, 0). These signals can also be represented by current pulses.
The Chair of Laser Physics has been studying how light waves can convert to current pulses for many years. The researchers used ultrashort laser pulses to illuminate the structure of graphene, gold electrodes and other materials. The laser pulses produce electron waves in graphene that move towards the gold electrodes. They can then be measured as current pulses, and processed as information.
As graphene is a pool, the gold electrodes act as an overflow basin. Some water will seep from the pool if the water surface is disturbed. Real charges can be compared to throwing a stone in the middle of a pool. Tobias Boolakee is the lead author and researcher at the Chair for Laser Physics.
“Virtual Charges are like scooping water from the edge without waiting for it to form waves. This is called a virtual charge because electrons are so fast that it is difficult to perceive. This would mean that the laser pulse would be directed towards the graphene’s edge, right next to the electrodes of gold. Both real and virtual charges can be read as binary logic
Lasers and logic
FAU’s laser physicists have demonstrated with their experiments that the method can be used in order to operate a logic gates – an essential element in computer processors. The logic gate controls how binary information (0 and 1) is processed. Two input signals are required for the gate, which is electron waves made of real and virtual charges. These waves are excited by two synchronized laser beams. The resulting current pulse can be either aggregated or erased depending on the strength and direction of the waves. The electrical signal measured by physicists can again be read as binary logic (0 or 1)
“This is a great example of how basic research can lead the development of new technology. We have discovered the role of virtual and real charges through fundamental theory and the connection to experiments. This has allowed us to create ultrafast logic gates,” said Ignacio Franco, University of Rochester.