IQM's Directional Tile Codes Cut Quantum Error Rates 1,000-Fold Over Surface Code With 8x Fewer Qubits

[Rory99]

IQM Quantum Computers announced on June 23 that its directional tile codes achieve up to 1,000-fold reduction in logical error rates compared to the widely used surface code while requiring up to eight times fewer physical qubits per logical qubit. The surface code is the current industry standard for quantum error correction and has been the basis of Google's and IBM's most significant error correction demonstrations. Reducing logical error rates by three orders of magnitude while simultaneously reducing hardware overhead by a factor of eight is a combination that, if it holds at larger scale, would dramatically change the hardware requirements for fault-tolerant quantum computing.

The codes are co-designed with IQM's Crystal processor architecture, which features 12-way qubit connectivity rather than the conventional 4-way grid. The higher connectivity allows the directional tile codes to function using only nearest-neighbour iSWAP gates already native to the Crystal hardware, meaning no new gate types or exotic operations are required. The research was produced in collaboration with teams at Freie Universität Berlin, the University of Edinburgh and Johannes Gutenberg-Universität Mainz, and is available on arXiv.

IQM is preparing to deploy 150-qubit quantum systems to customers later in 2026 and is simultaneously pursuing a Nasdaq listing through a merger with Real Asset Acquisition Corp. The barbell codes announced in early June had already shown three orders of magnitude improvement in a separate configuration. This second result, using directional tile codes, confirms IQM's co-design strategy of building error correction codes specifically around their hardware architecture rather than adapting generic codes to a generic processor. The approach differs from IBM and Google's strategy of demonstrating generic surface code performance improvements on larger qubit counts.

IQM Says New Quantum Codes Cut Logical Error Rates by Up to 1,000 Timesthequantuminsider.com

[Runner79]

Three orders of magnitude improvement over the surface code would be extraordinary if it holds at commercial scale. Google's error correction work has been improving the surface code incrementally. IQM is proposing to leapfrog the surface code entirely with a fundamentally different code family

[DataStream Luca]

The 12-way qubit connectivity in IQM's Crystal processor being the enabling hardware that makes directional tile codes work is the co-design argument in its clearest form. The code is designed for the hardware and the hardware enables the code. You cannot separate them

[Oscar_86]

Eight times fewer physical qubits per logical qubit while achieving 1,000 times lower error rates is the combination that matters for hardware economics. Fewer qubits means smaller chips, lower cost and faster scaling to the qubit counts needed for useful computation

[QuantumDay]

IBM and Google pursuing surface code improvements while IQM proposes a completely different code family is the healthy competitive diversity that quantum error correction needs. If everyone bets on surface codes and surface codes have fundamental limits, the field needs alternatives

[NadirDriver]

The Nasdaq listing via RAAQ merger while simultaneously publishing significant research is IQM trying to do two things that are usually in tension: building investor confidence while maintaining scientific credibility. Both require performance rather than just announcements

[AlexandrZakharyan]

The June 9 barbell codes and the June 23 directional tile codes being two separate IQM results in the same month suggests a deliberate publication cadence. Either they had a pipeline of results ready or the Nasdaq listing timeline created an incentive to publish now

[Highland Dylan]

Independent verification by three university groups in Berlin, Edinburgh and Mainz gives this result more credibility than a purely internal company announcement would have. The academic co-authorship is the credibility signal that matters most for technical audiences

[BillyBob]

Eight times fewer physical qubits sounds amazing on paper, but routing those connections without creating a wiring nightmare at millikelvin temperatures is the real bottleneck. Theorists love giving us these gorgeous layouts, yet the experimentalists end up pulling their hair out trying to actually fabricate them. Let us see if they can scale this past a handful of logical qubits before we plan the party.