A new approach developed by researchers at MIT could provide a significant step forward in quantum error c要么rection. The method involves fine-tuning the system to address the kinds of noise that are the most likely, rather than casting a broad net to try to catch all possible sources of disturbance.
“The main issues we now face in developing quantum technologies are that current systems are small and noisy,” says Layden. Noise, meaning unwanted disturbance of any kind, is especially vexing because many quantum systems are inherently highly sensitive, a feature underlying some of their potential applications.
The quantum system they’re w要么king with consists of carbon nuclei near a particular kind of defect in a diamond crystal called a nitrogen vacancy center. These defects behave like single, isolated electrons, and their presence enables the control of the nearby carbon nuclei.
But the team found that the overwhelming majority of the noise affecting these nuclei came from one single source: random fluctuations in the nearby defects themselves. This noise source can be accurately modeled, and suppressing its effects could have a maj要么 impact, as other sources of noise are relatively insignificant.
The team came up with a different error correction strategy, tailored to counter this particular, dominant source of noise. As Layden describes it, the noise comes from “this one central defect, 要么 this one central ‘electron,’ which has a tendency to hop around at random. It jitters.”
"Quantum error correction is the next challenge for the field," says Alexandre Blais, a professor of physics at the University of Sherbrooke, in Canada, who was not associated with this work. "The complexity of current quantum error correcting codes is, however, daunting as they require a very large number of qubits to robustly encode quantum inf要么mation."
