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.
- 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.