We know the maximum possible speed of computers

In our age of continuous technological advancement, we often feel that computing can evolve and improve endlessly. From memory capacity to computing speed, computers seem to have no limits. However, the laws of quantum physics do not agree.

at Article published in Nature magazine On March 25, 2022, Austrian researchers from the Technical University of Vienna (TU Wien) and the Technical University of Graz (TU Graz), as well as German scientists from the Max Planck Institute for Quantum Optics in Munich, were able to quantify it. Possible upper limit for computer speed.

As shown New AtlasThe maximum speed of computer chips is one million gigahertz. Or 100,000 times faster than the capacitance of transistors found in current computers, including quantum computers.

But if they manage to fix these theoretical limits of possibilities thanks to mathematics, researchers are nevertheless not entirely sure that human technology will one day be able to reach such an incredible speed.

Technically, there are only two ways to make computers faster: One is to reduce the size of computer components. The idea? Shortening the distance that data transmission signals must travel between point A and point B.

The second is to speed up the signals sent by the transistors by removing any barriers that might slow the flow of current. In this endeavor, light plays a major role. Since nothing travels faster than light, systems that use light to control electricity, are known as optoelectronicsare the fastest devices.

And there was light

To find their results, the team of Austrian and German physicists conducted practical experiments. They fired a very short laser pulse at the semiconductor to move the material’s electrons to a higher energy state, allowing them to move freely.

In a second step, they make a second laser pulse, a bit longer, to turn these electrons back in a specific direction, to artificially produce a faster electric current.

After several attempts, with increasingly shorter laser pulses, the scientists succeeded in calculating the absolute limit to the speed that optoelectronic systems can reach: one petahertz, or one million gigahertz, the unit of frequency. Note: When it comes to computer speed, the search uses the term “high frequency” to mean “fast”.

If you are curious and have a desire to listen to applied physics with an Irish accent, Professor Phil Moriarty from the University of Nottingham He explains the limits of technology on Computerphile’s YouTube channel. For less specialists, we leave you at Very good video summary To (finally) understand all about these stories about quantum computers…