Error mitigation is route to useful quantum computing, says IBM
Author: EIS Release Date: Jul 26, 2022
A common refrain in the quantum computing field is that if you want value from a quantum computer, it needs a large, fault tolerant quantum processor – nothing else can implement quantum algorithms that perform better than classical devices.
Until then we’re stuck in the NISQ (Noisy Intermediate-Scale Quantum) era of noisy devices that are inferior to classical counterparts.
“Our team has a different view,” says IBM, “we have created new techniques to draw ever more value from noisy qubits. That means we’ve left the NISQ era behind. But instead of reaching for a fault tolerant computer, we’re instead relying on continuous and incremental improvements to quantum technology.”
IBM has produced a paper https://research.ibm.com/blog/gammabar-for-quantum-advantage which details the tools and techniques that deliver the following improvements:
Error Mitigation
Probabilistic error cancellation – This is secret sauce technique whereby we effectively invert noisy circuits – so we can get error-free results, even though the circuits themselves are noisy.
Scale
In 2021, IBM unveiled the 127-qubit Eagle processor, the first quantum processor capable of quantum circuits that can’t be simulated classically.
Detailed in the expanded quantum roadmap we unveiled in May, the number of qubits within our systems is on track to reach 4,000+ in 2023. As laid out in this vision, the milestones we have mapped to increase the power, quality, and accessibility of quantum hardware and software will serve as the foundation for quantum advantage.
Hardware improvements
Even after larger processors are unveiled, we keep improving their performance as they are fabbed at our Research HQ in Yorktown Heights, NY.
One of these improvements is in the coherence of the qubits; We’ve more than doubled the coherence times on our 65 qubit chips since they were unveiled in 2020, and every improvement further reduces the errors in the quantum circuits.