Quantum Experiment Reveals Speed Limit for Electronics

In a Simpson’s episode, Bart, who doesn’t believe in souls, sells his to Milhouse for $5. Bart sells his soul, only to later regret it and be unable to get it back. The drama reaches a peak when Bart gets to eat the physical piece of paper on which he scribbled “Bart Simpson’s Soul.” It’s a simple answer, but how do you get your soul back after selling it as a non-fungible token (NFT)? The cryptocurrency-NFT chapters of humanity’s fall from the light have officially entered the “selling my soul” phase, so we may soon find out.

There is, however, a limit. Controlled processes involving light and electronics in materials cannot exceed one petahertz, according to the study, which was published in Nature Communications. This equates to almost 1,000 trillion processes per second. Commercially available CPUs have a clock frequency of around 4.5 gigahertz; therefore the speed limit is more than 250,000 times higher. In a statement, co-author Prof. Christoph Lemell of TU Wien remarked, “For a long time, such processes were regarded instantaneous.” “Today, however, we have the technology to investigate the time evolution of these ultrafast processes in more depth.”

The uncertainty principle, which is one of quantum mechanics’ cornerstones, gives rise to the limit. You may have heard it defined as: the more accurately you know a particle’s position, the less exactly you can estimate its momentum, and vice versa. This holds true for both energy and time. As a result, shorter laser pulses are required at quicker speeds, implying that the energy is not precisely defined. And energy is crucial. Free electrons are required for electricity to flow, and the energy supplied to the system can remove the electrons from the atoms. As a result, if the energy you give is unknown, your system may not perform as expected above a specific threshold of short-time pulses.

“We can pinpoint when the free charge carriers are formed, but not in which energy state they are created,” Lemell explained. “Solids have different energy bands, and many of them are necessarily occupied by free charge carriers at the same time when short laser pulses are used.” While the petahertz is a lovely round number, the team believes that electronics will never get close to it. Other physical attributes relating to the individual materials and arrangement should be investigated in order to determine the true physical speed limit. But, at the very least, there are now methods for reaching such boundaries.