Light-Controlled Ultra-Fast Computer Achieves Speeds Over 100 Times Faster Than Electronic Devices

Recently, an international research team led by the Politecnico di Milano in Italy, in collaboration with the Institute for Photonics and Nanotechnologies of the Italian National Research Council (CNR-IFN), has successfully developed an ultra-fast computer controlled by light. The team achieved ultra-fast logic operations in novel two-dimensional semiconductor materials using femtosecond laser pulses, reaching speeds more than 100 times faster than the fastest electronic devices available today. This achievement demonstrates for the first time that light can not only transmit information but also directly process it, opening new pathways for breakthroughs in future computing performance. The related paper has been published in the latest issue of *Nature Photonics*.

Modern computers rely on the movement of electrical charges within transistors for computation, which is increasingly approaching physical limits. This research adopts a fundamentally different approach: using oscillating light fields to directly manipulate the quantum states of electrons in materials. The researchers employed tungsten disulfide, a two-dimensional semiconductor just three atoms thick, as the medium. In this material, electrons can occupy two distinct quantum states, known as "valleys." These two states can correspond to the traditional binary "0" and "1," but offer far greater manipulation potential than electrical charges.

In the experiment, the team applied a series of precise laser pulses lasting only a few femtoseconds. They successfully switched and expanded information between these two "valley" states at room temperature, performing basic operations analogous to electronic logic gates at speeds exceeding 10 terahertz. The entire process was conducted at ambient temperature, and the optical pulse technology used is already routine in laboratories, highlighting the technical feasibility.

The research team noted that the technology is still in the proof-of-principle stage. Transforming it into competitive computing devices faces several challenges, including designing more complex pulse sequences and scaling up the number of operable bits. Overcoming these obstacles will lay the foundation for developing a new generation of ultra-fast information processors, potentially leading to computing devices hundreds of times faster than current technology.