Researchers from MIT and the Pacific Northwest National Laboratory have discovered that cosmic rays are causing errors in quantum computers’ calculations, reported VICE. The findings published on Wednesday in the journal Nature solve the mystery about the origin of these faults known as quasiparticle poisoning.
What the team discovered was that environmental radiation, such as that found in beta particles, destroys bonded electrons, disturbing qubits in the process. This reduces the lifespan of a qubit to just a few milliseconds.
Qubits currently last less than a thousandth of a millisecond. Therefore if we want to achieve practical quantum computing, we need to solve the radiation problem.
The groundbreaking research began when Pacific Northwest National Laboratory nuclear physicist Brent VanDevender wanted to borrow equipment from William Oliver, a quantum information researcher. During this process, Oliver told VanDevender that quantum computing had been plagued by an unnatural amount of quasiparticles and revealed that environmental radiation was being considered as one hypothesis.
“Neutrino physicists and dark matter physicists deal with mitigating the effects of radiation all the time—it's one of the hardest parts of our life,” VanDevender told VICE. “It was really natural for us to work with Will Oliver to test that hypothesis, which is what the paper is about.”
The researchers further noted that although once revealed in their study their findings might seem obvious, they were first met with much resistance.
“After the fact, when we said, 'We've demonstrated that radiation is a source of excess quasiparticles,' everyone said, 'Well yeah, that's obvious,'” Ben Loer, a staff physicist at Pacific Northwest National Laboratory and a co-author of the study told VICE. “But those same people six months earlier—it hadn’t seemed to occur to anybody.”
Luckily for the science community at large, the researchers were not deterred and their work finally proves that quantum computing is indeed affected by cosmic radiation. Now the team is working to determine how exactly each form of radiation affects quasiparticle formation.