Major milestones in the race toward practical, fault-tolerant quantum computing were achieved in September 2025, with breakthroughs centered on increasing qubit count, enhancing operational stability, and demonstrating real-world commercial value.
In a significant advance for scaling up quantum systems, Harvard scientists unveiled a system exceeding 3,000 qubits ten times larger than previous efforts that is capable of continuous operation without the need for frequent restarts. This was accomplished by implementing “optical lattice conveyor belts” and “optical tweezers” to continually and rapidly resupply lost qubits, with the system reloading up to 300,000 atoms per second.
Separately, Caltech scientists built an even larger record-breaking array of 6,100 neutral-atom qubits, maintaining long-lasting superposition and exceptional accuracy even while the qubits were physically moved.
Leading commercial quantum companies also reported major progress. IonQ announced it had achieved a record algorithmic qubit score of AQ 64 on its IonQ Tempo system, establishing a new performance standard. This achievement significantly doubles the useful computational space for algorithms, with the company suggesting the system is approaching commercial advantage for certain complex applications.
Furthermore, Alice & Bob, a quantum computing firm, demonstrated major advances in error resilience by achieving bit-flip times exceeding one hour on their “cat qubits,” directly addressing a major obstacle to creating stable, fault-tolerant machines.
A critical hurdle in mass production was cleared when the UNSW Sydney startup Diraq successfully fabricated its silicon-based quantum chips using standard, industrial semiconductor foundry processes at imec. These chips maintained the over 99% accuracy required for fault-tolerant operation, proving that silicon qubits can be built cost-effectively and are compatible with the trillion-dollar microchip industry.
Finally, the technology demonstrated its first concrete commercial value in the financial sector. HSBC and IBM announced the world’s first-known empirical evidence of quantum-enabled algorithmic trading, using a hybrid quantum-classical approach to improve predictions for bond trading in the European corporate bond market by up to 34%. This experiment provides a tangible example of how today’s quantum computers can deliver a measurable competitive advantage in real-world business problems.