Ibm Updates Path To Fault Tolerant Quantum Computing

Bonisiwe Shabane

-Dec 4, 2025, 6:39 PM

ibm updates path to fault tolerant quantum computing

With two new research papers and an updated quantum roadmap, IBM® lays out a clear, rigorous, comprehensive framework for realizing a large-scale, fault-tolerant quantum computer by 2029. IBM has the most viable path to realize fault-tolerant quantum computing. By 2029, we will deliver IBM Quantum Starling — a large-scale, fault-tolerant quantum computer capable of running quantum circuits comprising 100 million quantum gates on 200 logical qubits. We are building this system at our historic facility in Poughkeepsie, New York. Watch our new video, 'Realizing large-scale, fault-tolerant quantum computing,' on YouTube. In a new paper, now available on the arXiv1, we detail a rigorous end-to-end framework for a fault-tolerant quantum computer that is modular and based on the bivariate bicycle codes we introduced with our...

Additionally, we’re releasing a second paper3 that details the first-ever accurate, fast, compact, and flexible error correction decoder — one that is amenable to efficient implementation on FPGAs or ASICs for real-time decoding. We’ve updated our roadmap to match, with new processors and capabilities that will pave the way to quantum advantage, Starling, and fault tolerance. Watch the 2025 IBM Quantum Roadmap update on YouTube. June 10 2025 IBM made a landmark announcement outlining a clear path to build the world’s first large-scale, fault-tolerant quantum computer by the year 2029. Codenamed IBM Quantum “Starling,” this planned system will leverage a new scalable architecture to achieve on the order of 200 logical (error-corrected) qubits capable of executing 100 million quantum gates in a single computation. IBM’s quantum leaders described this as “cracking the code to quantum error correction” – a breakthrough turning the long-held dream of useful quantum computing from fragile theory into an engineering reality.

IBM used the occasion of quantum computing roadmap update to declare that it now has “the most viable path to realize fault-tolerant quantum computing” and is confident it will deliver a useful, large-scale quantum... The centerpiece of this plan is IBM Quantum Starling, a new processor and system architecture that IBM says will be constructed at its Poughkeepsie, NY facility – a site steeped in IBM computing history. Starling is slated to feature about 200 logical qubits (quantum bits protected by error correction) spread across a modular multi-chip system, rather than a single huge chip. According to IBM, Starling will be capable of running quantum circuits with 100 million quantum gate operations on those logical qubits. For context, that is orders of magnitude beyond what today’s noisy intermediate-scale quantum (NISQ) processors can reliably do. IBM emphasizes that achieving this will mark the first practical, error-corrected quantum computer – a machine able to tackle real-world problems beyond the reach of classical supercomputers, thanks to its scale and reliability.

A core theme of IBM’s announcement is the transition from today’s “fragile, monolithic” chip designs toward modular, scalable, error-corrected systems. Up to now, IBM (and most industry players) built quantum processors on single chips with qubits laid out in a planar array (IBM’s 127-qubit Eagle and 433-qubit Osprey chips are examples). These monolithic chips are limited in size and are not error-corrected – more qubits tend to introduce more noise. IBM’s new approach with Starling is modular quantum hardware: multiple smaller chips or modules will be interconnected via quantum links, allowing qubits in different modules to interact as if on one chip. IBM previewed this modular design with its IBM Quantum System Two infrastructure and experiments like the “Flamingo” coupler that demonstrated microwave links between chips. By distributing qubits across replaceable modules connected quantumly, IBM can scale to much larger qubit counts than a single chip can support.

Crucially, this modularity is paired with long-range entanglement – qubits on different chips can be entangled through couplers, overcoming the short-range connectivity limitations of a 2D chip lattice. IBM’s 2025 roadmap calls for a stepwise implementation of this modular architecture: for example, IBM Quantum “Loon” (expected in 2025) will test the new inter-chip couplers and other components, followed by Kookaburra (2026) to... All these lead up to Starling as the first full-scale fault-tolerant system in 2028–2029. In short, IBM is moving from building bigger single chips to building better systems of chips – a modular quantum compute unit that can be expanded piece by piece. Perhaps the most significant technical breakthrough underpinning IBM’s plan is its quantum error correction (QEC) scheme. Rather than the well-known “surface codes” used by others (which arrange qubits in a 2D grid with local redundancy), IBM is betting on quantum low-density parity-check (LDPC) codes – specifically a family of codes...

In simple terms, QEC works by encoding one “logical” qubit of information into many physical qubits, so that if some of the physical qubits get corrupted by noise, the logical information can still be... Surface codes typically might need on the order of ~1,000 physical qubits to encode 1 logical qubit at an error rate suitable for large algorithms. IBM’s new LDPC-based code is far more resource-efficient: for example, one instance encodes 12 logical qubits in 288 physical qubits (a [[144,12,12]] code), achieving the same error suppression as surface code but with an... This is a game-changer for scalability – it means far fewer physical qubits are required to achieve a given computing capability. IBM’s Vice President of Quantum, Dr. Jay Gambetta, boldly stated, “We’ve cracked the code to quantum error correction”, describing the new architecture as “an order of magnitude or more more efficient” than surface-code-based approaches.

By combining these LDPC codes with the modular hardware (which provides the long-range connectivity the codes require), IBM’s “bicycle architecture” can create logical qubits that are robust against errors without impractical overhead. The bottom line: IBM’s Starling will use error-corrected logical qubits from day one, not just raw physical qubits. IBM believes this development cracks the last big scientific hurdle and that nothing fundamentally unknown remains – it’s now a matter of engineering scale and integrating the system. Overall, IBM’s June 2025 news marks a pivot point in quantum computing. The company has publicly committed to a deadline – a 200-logical-qubit fault-tolerant quantum computer by 2029 – and backed it up with a detailed roadmap of intermediate milestones and a stack of research results... They are moving beyond incremental qubit count increases toward a full stack redesign: new codes, new chips, new interconnects, new cryogenic infrastructure, and co-designed software (IBM’s updated Qiskit Runtime and error mitigation tools were...

This cohesive effort has led analysts to note that IBM appears to have “solved the scientific obstacles to error correction” and now holds “the only realistic path” toward building such a machine on the... In the next section, we’ll analyze what this breakthrough means for the wider industry and, critically, for cybersecurity experts who worry about quantum threats to encryption. IBM has updated its roadmap for building large-scale, fault-tolerant quantum computers, setting the stage for practical and scalable quantum computing. A quantum computer of this kind, with hundreds or thousands of logical qubits, could run hundreds of millions to billions of operations, which could accelerate time and cost efficiencies in fields such as drug... However, the success of executing an efficient fault-tolerant architecture is dependent on the choice of its error-correcting code, and how the system is designed and built to enable this code to scale. Error-correcting codes needed for more powerful quantum computers require an unfeasible number of physical qubits, which provide enough logical qubits to perform complex operations.

According to IBM, scaling error-correcting code also means the amount of infrastructure and control electronics needed is impractical beyond small-scale experiments and devices. IBM has set its sights on a new approach to quantum error correction using low-density parity-check codes in a modular approach to quantum computing known as bicycle architecture. IBM announced an ambitious roadmap for quantum computing, aiming to deliver the IBM Quantum Starling, a large-scale, fault-tolerant quantum computer, by 2029. Key focuses include modular processor design, error correction, and scalable communication networks. The plans also extend to quantum-centric supercomputers by 2033, promoting practical applications across various industries. Quantum computing promises to revolutionize industries by solving complex problems beyond the reach of classical computers.

IBM, a pioneer in quantum research, recently announced an ambitious roadmap to deliver the world’s first large-scale, fault-tolerant quantum computer, named IBM Quantum Starling, by 2029, with plans for quantum-centric supercomputers by 2033. On June 10, 2025, IBM unveiled a comprehensive quantum computing roadmap aimed at achieving a practical, large-scale, fault-tolerant quantum computer by 2029. The announcement, detailed across various sources, outlines a full-stack strategy centered on three key pillars: modular processor design, real-time decoding for fault tolerance, and scalable quantum communication networks. The system, dubbed IBM Quantum Starling, is set to be developed at IBM’s quantum data center in New York, marking a significant milestone in the company’s quantum ambitions. IBM’s press release emphasizes incremental advancements leading to 2029. Unlike previous roadmaps that focused on qubit count milestones—such as the 1,000+ qubit chip unveiled in 2023—the new strategy prioritizes fault tolerance and scalability to achieve practical quantum computing applications.

The roadmap also includes plans for quantum-centric supercomputers by 2033, capable of running 1 billion quantum gates with thousands of qubits, unlocking the full potential of quantum computing for real-world use cases like drug... “Our roadmap to 2029 is a clear path to fault-tolerant quantum computing. By focusing on modularity, error correction, and scalable networks, we’re building a system that will deliver real value to industries and academia.” Dr. Jay Gambetta, IBM’s Vice President of Quantum ComputingSource: IBM Press Release, June 2025 (paraphrased from roadmap announcement). IBM has just made a major announcement about its plans to achieve large-scale quantum fault tolerance before the end of this decade. Based on the company’s new quantum roadmap, by 2029 IBM expects to be able to run accurate quantum circuits with hundreds of logical qubits and hundreds of millions of gate operations.

If all goes according to plan, this stands to be an accomplishment with sweeping effects across the quantum market — and potentially for computing as a whole. In advance of this announcement, I received a private briefing from IBM and engaged in detailed correspondence with some of its quantum researchers for more context. (Note: IBM is an advisory client of my firm, Moor Insights & Strategy.) The release of the new roadmap offers a good opportunity to review what IBM has already accomplished in quantum, how it... First, we need some background on why fault tolerance is so important. Today’s quantum computers have the potential, but not yet the broader capability, to solve complex problems beyond the reach of our most powerful classical supercomputers. The current generation of quantum computers are fundamentally limited by high error rates that are difficult to correct and that prevent complex quantum algorithms from running at scale.

While there are numerous challenges being tackled by quantum researchers around the world, there is broad agreement that these error rates are a major hurdle to be cleared. In this context, it is important to understand the difference between fault tolerance and quantum error correction. QEC uses specialized measurements to detect errors in encoded qubits. And although it is also a core mechanism used in fault tolerance, QEC alone can only go so far. Without fault-tolerant circuit designs in place, errors that occur during operations or even in the correction process can spread and accumulate, making it exponentially more difficult for QEC on its own to maintain logical... Reaching well beyond QEC, fault-tolerant quantum computing is a very large and complex engineering challenge that applies a broad approach to errors.

FTQC not only protects individual computational qubits from errors, but also systemically prevents errors from spreading. It achieves this by employing clever fault-tolerant circuit designs, and by making use of a system’s noise threshold — that is, the maximum level of errors the system can handle and still function correctly. Achieving the reliability of FTQC also requires more qubits. IBM has announced a bold vision to deliver the world’s first large-scale, fault-tolerant quantum computer, marking a pivotal step toward practical and scalable quantum computing. The company’s latest roadmap, unveiled alongside this announcement, details a clear path to overcoming the technical barriers that have long limited quantum systems to experimental and small-scale applications. Central to IBM’s strategy is the IBM Quantum Starling, a system anticipated for delivery in 2029.

This quantum computer will be housed in a new IBM Quantum Data Center in Poughkeepsie, NY, and is projected to execute 20,000 times more operations than today’s quantum computers. The computational state of Starling is so vast that representing it would require more memory than a quindecillion (10^48) of the world’s most powerful supercomputers combined. With this leap, users will be able to explore quantum states and computational complexity far beyond the reach of current quantum systems. IBM’s global fleet of quantum computers already leads the industry. Still, the new roadmap sets the stage for a practical, fault-tolerant quantum computer capable of addressing real-world business and scientific challenges. Arvind Krishna, IBM’s Chairman and CEO, emphasized that the company’s progress is rooted in its deep expertise in mathematics, physics, and engineering, all directed toward building a quantum computer that can solve meaningful problems...

A large-scale, fault-tolerant quantum computer, one with hundreds or thousands of logical qubits, could perform hundreds of millions to billions of operations. This capability has the potential to transform industries by dramatically improving time and cost efficiencies in fields such as drug discovery, materials science, chemistry, and complex optimization. IBM Quantum Starling will be the first to run 100 million quantum operations using 200 logical qubits, laying the foundation for the next-generation IBM Quantum Blue Jay, which will scale to 1 billion operations... Logical qubits, the building blocks of error-corrected quantum computers, are constructed from clusters of physical qubits that work together to store quantum information and monitor for errors. This architecture is essential for suppressing errors and enabling large-scale, reliable quantum computation.

Ibm Updates Path To Fault Tolerant Quantum Computing

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