By Pavlos Dracopoulos (RES - MPE)
One group Chinese scientists announced that they have carried out the first undisputed demonstration of the so-called «quantum advantage» (a term that replaced the older «quantum supremacy»), exploiting the quantum mechanics to perform calculations that are impossible on conventional computers.
This is the second time such an announcement has been made, preceded by the US Google in 2019, but doubts were expressed as to whether it was - indeed - quantum supremacy. Other scientists had argued at the time that a better classical algorithm was possible that could outperform the quantum computer Sycamore Google.
The researchers, led by Jian-Way Παν of China University of Science and Technology in Hefei, who published the paper in the journal «Science.», according to the «Nature.» and the «New Scientist», said that the quantum calculations they achieved in just a few minutes (200 seconds), using laser beams of light, would take 600 million years to perform on the world's most powerful supercomputer, the Japanese Fugaku, or two and a half billion years (half the age of the Earth!) to run on the most powerful Chinese supercomputer and the world's No. 4, the Sunway TaihuLight.
«We showed that we can use photons, the fundamental unit of light, to achieve quantum computing power far beyond classical computers.», said Pan. It is the first time the quantum advantage has been achieved using photonics.
An «important milestone» was mentioned by the physicist Ian Walsley of Imperial College London. But he clarified that - unlike Google's Sycamore quantum computer - the Chinese quantum algorithm cannot be programmed, therefore cannot be used to solve practical problems, but this may become possible in the future, to be used in e.g. quantum cryptography or quantum chemistry.
