Researchers Calculate Ultimate Speed Limit For Electronics

May, 2022 - By WMR

Scientists calculated the absolute high limit of speed of optoelectronic systems, before quantum mechanics hampers them and their performance

It is often considered that electronics such as computer chips can keep getting faster with time, however, these electronics at some point face physical limits that stops them. Now researchers from TU Graz, TU Wien, and the Max Planck Institute of Quantum Optics explored these limits and calculated the absolute upper limit for optoelectronic systems that prevents them from getting faster to the points where quantum mechanics can mess them up.

Optoelectronics are the systems that use light for controlling electricity and known to be the fastest devices. The team of researchers now have found the upper limit even for these devices. In this study, the researchers used semiconductor materials and lasers. The study involved hitting the semiconductor with an ultra-short laser pulse that turns electrons in the material into a higher state of energy. This allows them to move around freely. Then with the second laser pulse that a bit stronger these electronics are shot in a specific direction and generate an electric current. With this technique and a complex computer simulations, the researchers exposed semiconductors to shorter laser pulses. However, at a point this process starts to collide with Heisenberg’s uncertainty principle, a quantum quirk where characteristics of each particle are different.

With this, it was discovered that the use of shorter pulses can predict the exact moment when the electrons gain energy, however, this method can be uncertain about the amount of energy gain, which limits electronics and this helped the team to identify the ultimate speed limit of 1 Petahertz, which is a million Gigahertz for optoelectronic systems. According to the team, optoelectronic devices would face other limitations before reaching the realm of PHz. However, understanding of the hard limit would lead to development of better electronics.