from the simply-get-them-to-give-up-drinking dept.
Correcting the jitters in quantum devices:
Labs around the world are racing to develop new computing and sensing devices that operate on the principles of quantum mechanics and could offer dramatic advantages over their classical counterparts. But these technologies still face several challenges, and one of the most significant is how to deal with "noise"—random fluctuations that can eradicate the data stored in such devices.
A new approach developed by researchers at MIT could provide a significant step forward in quantum error correction. 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 analysis is described in the journal Physical Review Letters, in a paper by MIT graduate student David Layden, postdoc Mo Chen, and professor of nuclear science and engineering Paola Cappellaro.
"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.
[...] we just don't have the resources to do particularly useful quantum error correction in the usual way." So instead, the researchers found a way to target the error correction very narrowly at the specific kinds of noise that were most prevalent.
The quantum system they're working 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.
[...] "The upshot of our approach is that we're able to get a fixed level of protection using far fewer resources than would otherwise be needed," he says. "We can use a much smaller system with this targeted approach."
The work so far is theoretical, and the team is actively working on a lab demonstration of this principle in action. If it works as expected, this could make up an important component of future quantum-based technologies of various kinds, the researchers say, including quantum computers that could potentially solve previously unsolvable problems, or quantum communications systems that could be immune to snooping, or highly sensitive sensor systems.
Journal Reference:
David Layden, Mo Chen, and Paola Cappellaro. "Efficient Quantum Error Correction of Dephasing Induced by a Common Fluctuator", Physical Review Letters (2020). DOI: 10.1103/PhysRevLett.124.020504
