Error-corrected qubits 800 times more reliable after breakthrough, paving the way for 'next level' of quantum computing

Scientists have created a set of "logical qubits" that have error rates 800 times lower than physical qubits — paving the way for useful, fault-tolerant quantum computers in the near future.

Quantum bits, or qubits, are inherently prone to error — this susceptibility is described as being "noisy." Creating logical qubits is one way of solving this. These are a collection of physical qubits that are tied through quantum entanglement — and they reduce errors by storing the same information in different places. This spreads out the possible points of failure while a calculation is underway.

In a new paper published April 2 to the preprint server arXiv, scientists demonstrated they could perform experiments on four logical qubits made using 30 of the 32 physical qubits in the H2 quantum processor made by Quantinuum, a quantum computing company. 

The team, made up of researchers from Quantinuum and Microsoft, ran 14,000 experiments on a basic quantum circuit made up of the logical qubits without generating any errors that weren't detected and corrected. 

They hope this technology can be integrated into a future hybrid supercomputer powered by 100 reliable logical qubits — which would be enough to provide organizations with a scientific advantage, Microsoft's EVP for strategic missions and technologies said April 3 in a blog entry. 

Related: World's 1st fault-tolerant quantum computer launching this year ahead of a 10,000-qubit machine in 2026

One of the biggest problems with scaling quantum computers, beyond the hardware required to run them, is the extremely high error rates of qubits. Bits in conventional computing have an error rate of 1 in 1 billion billion.