Ultrafast computers controlled by light
Extremely short light pulses for performing ultrafast logical operations: this is the result of the study published in the journal Nature Photonics, carried out by a group of researchers from the Department of Physics at Politecnico di Milano, in collaboration with the Institute of Photonics and Nanotechnologies of the National Research Council (CNR-IFN) and with international research centers.
Currently, computers operate thanks to the movement of electrical charges inside transistors. However, this process imposes physical limits on the maximum speed at which devices can operate. Unlike traditional electronics, the new approach manipulates the state of electrons in matter by the use of oscillating light, allowing logic operations at much higher frequencies.
We have shown that light can be used not only to transmit information, but also to process it. With the use of ultra-short laser pulses, we can control the quantum states of matter on time scales of a few millionths of a billionth of a second, i.e., at the same frequencies as light oscillation, speeds previously unknown in electronics.” Giulio Cerullo, professor of the Department of Physics.
Giulio Cerullo, professor of the Department of Physics
The experiments were carried out using a two-dimensional semiconductor, tungsten disulfide (WS₂), which is only three atomic layers thick. Through sequences of laser pulses lasting a few femtoseconds, the researchers managed to turn on, turn off, and expand information selectively, performing operations at frequencies above 10 terahertz, over a hundred times higher than the best modern electronic devices, thus demonstrating an important step toward a new generation of technologies for information processing.
The project is coordinated by Giulio Cerullo, faculty member at Politecnico di Milano, with the participation of faculty Stefano Dal Conte and Margherita Maiuri, and researchers Francesco Gucci, first author of the article, and Mattia Russo. For CNR-IFN, researcher Franco Camargo contributed.