Advanced quantum computer made available to the public for first time
A quantum computer is a device that harnesses the properties of atoms and photons to perform calculations far beyond what any conventional computer could ever hope to achieve. These devices are not yet commercially available, but scientists around the world are working on them. One type of quantum computer uses individual atoms trapped inside an electromagnetic trap. Another type uses photons instead of electrons to encode information. Both types require extremely cold temperatures. The first quantum computer to demonstrate “quantum supremacy” was built by Google. It took less than half a second to solve a problem that would normally take a conventional computer thousands of years to complete. Researchers say that a fully functioning quantum computer will be available within five years.
A quantum computer relies on the strange properties of Quantum Mechanics to theoretically perform certain calculations much faster than conventional computers. A longstanding goal in the field, called quantum advantage or quantum supremacy has been to demonstrate that a quantum computer can actually beat regular computers. Google was the first company to do so in 2019 when it demonstrated a quantum advantage using its Sycamore processor.
Now, researchers at the University of Waterloo in Ontario, Canada, and the National Institute of Standards and Technology in Boulder, Colorado, have built a quantum computer using photons instead of electrons. Called Borealis, the device uses a series of optical fibres to link together a number of photon sources, each of which emits single photons. These photons are then sent along a network of optical fibres to a detector. The team found that when they measured the properties of all the photons simultaneously, they were able to determine whether the photons had been emitted in pairs or not. If the photons were linked, the team could also measure the difference in energy between them. This allowed them to calculate the probability of finding the two photons in different states. By repeating the experiment many times, the team found that the photons behaved like a randomised version of a boson, meaning that they followed a distribution similar to what you’d expect if they were behaving according to the laws of quantum mechanics.
