We all know about the ongoing efforts to build a Quantum Computer by encoding information into quantum states of particles of light (photons), however there is a parallel effort ongoing that is trying to build Quantum Computers that are based on Sound instead of light. This effort being led by Andrew Cleland at the University of Chicago, just had a major breakthrough and created a device that is a key component in building a sound based Quantum Computer.
Phonons are the fundamental quantum vibrations within materials, with individual phonons representing the collective motion of many trillions of atoms. The team built a chip that allows them to create single phonons on demand which are about a million times higher pitched than audible sound. They then passed it into a beam splitter which consists of 16 tiny, parallel aluminium strips designed so that any sound that hits them gets reflected and transmitted in equal parts. At supercooled temperatures they found that the Phonon entered a quantum superposition state where the whole particle was simultaneously in the state of being reflected and transmitted.
Cleland says that this is exactly what they hoped would happen because this process is a necessary step for running calculations on quantum computers that rely on particles of light. To make their chip even more like a sound-based quantum computer, the researchers also successfully recreated the way two particles of light are commonly made to “talk to each other” and how their behaviour is controlled during light-based computations.
Here, they simultaneously sent two phonons from opposite directions into the beam splitter and saw their respective superposition states influence each other. In the future, they will use this procedure to implement simple operations that make up computer programs.
Dirk Bouwmeester at the University of California, Santa Barbara, says that for particles of light, procedures like quantum teleportation or creating entanglement hinge on using beam splitters, and now they could be done with particles of sound as well. “It is truly spectacular that the team could replace photons with phonons,” he says.
There are a lot of interesting applications for this technology once it matures, for example it could be used to connect computer components that are hard to connect to each other. Using sound as the carrier instead of light opens up more possibilities. Their research has been published in the Science Journal (DOI: 10.1126/science.adg8715)
Source: NewScientist: Sound-based quantum computers could be built using chip-sized device
– Suramya