IBM Achieves Quantum Computing Milestone with 70 Logical Qubits and Enhanced Error Correction
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Written by
Simonas Brazionis - Updated 2026-07-31 06:30:36
IBM has announced a significant achievement in quantum computing, demonstrating what it calls “trusted quantum advantage” through an experiment involving 70 logical qubits and a new error-correction method. This development represents progress in the field of quantum computation. The experiment successfully completed a computation that surpasses the capabilities of current classical simulation methods, with statistical evidence supporting the accuracy of the result.
This achievement is considered a key step in IBM's quantum roadmap. While the hardware used in this experiment is not yet capable of posing a threat to Bitcoin's security, the research contributes to overcoming the challenge of reliably correcting errors in quantum systems as they scale.
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Understanding Trusted Quantum Advantage
Quantum advantage refers to the ability of a quantum computer to solve a practical problem more efficiently than a classical computer. Jay Gambetta, Director of IBM Research, stated that the era of quantum advantage has commenced, establishing a new foundation for trust in quantum computers as they expand. IBM's researchers encoded 70 logical qubits, employing a new error-correction technique.
The computation was completed in approximately 15 minutes, a task that would demand impractical amounts of time using current classical simulation methods. The experiment involved 2,415 logical two-qubit operations and 468 logical T gates, reducing logical error rates to about one-tenth of the underlying physical error rate.
Verifying Quantum Advantage and IBM's Roadmap
IBM addressed criticisms regarding the verification of quantum advantage demonstrations by developing a structured alternative to traditional random circuit sampling. This alternative enables error detection during computation while maintaining mathematical difficulty. Bill Fefferman, Associate Professor at the University of Chicago, noted that verification is a major challenge in establishing experimental quantum advantage.
He added that the experiment develops techniques to characterize the fidelity of hard quantum states under noise, increasing confidence in the quantum computer's problem-solving ability. IBM's Starling roadmap, released in June, aims for a large-scale fault-tolerant quantum computer by 2029.
Implications for Bitcoin Security
The roadmap outlines steps including verified quantum advantage demonstrations, scaling to modular processors, and achieving a system with approximately 200 logical qubits and 100 million quantum operations. In October 2025, researchers demonstrated a 120-qubit GHZ “cat state.” A month later, the 120-qubit Nighthawk processor and experimental Loon chip were introduced. Earlier this year, IBM expanded public access to advanced quantum hardware.
The latest experiment is considered an incremental technical advance towards a “Q-Day” for Bitcoin. Bitcoin utilizes elliptic curve cryptography for digital signatures. Breaking Bitcoin's encryption would necessitate thousands of logical qubits on a fault-tolerant quantum computer, whereas IBM's latest experiment demonstrated 70 logical qubits.
