Chinese physicists at the University of Science and Technology of China (USTC) published a study in Nature on Wednesday revealing that their room-temperature photonic processor, Jiuzhang 4.0, completed a standard quantum benchmark calculation in 25 microseconds—a task the U.S. Department of Energy's El Capitan, currently the world's fastest supercomputer, would require more than 1042 years (tredecillion years) to finish. The result, achieved without the cryogenic infrastructure that rivals such as Google and IBM depend on, sharpens a geopolitical contest over quantum computing in which control of this technology—and the encrypted communications it could eventually break—is increasingly treated as a national security matter.
3,050 Photons at Room Temperature, No Cooling Required
Jiuzhang 4.0 manipulates and detects up to 3,050 photons simultaneously—more than twelve times the 255 photons achieved by its predecessor, Jiuzhang 3.0, which itself held the world record. The system integrates 1,024 high-efficiency squeezed-state light inputs across an 8,176-mode interferometric circuit. USTC professor Lu Chaoyang, who led the engineering effort, said the team developed a high-efficiency optical parametric oscillator light source and a spatiotemporally hybrid-coded interferometer to achieve the scale.
The photonic architecture encodes quantum information in particles of light rather than in superconducting circuits. That distinction carries a significant practical consequence: superconducting systems used by Google and IBM must be cooled to temperatures near absolute zero (roughly −273°C) to function. Jiuzhang 4.0 operates at room temperature, removing a principal barrier to deployment outside specialist laboratory settings.
A Benchmark Win, Not Yet a Commercial Tool
The calculation Jiuzhang 4.0 performed is Gaussian boson sampling—a problem mathematically structured to expose the gap between quantum and classical processors, but one with no direct commercial application. Researchers at Xanadu and academics at PennyLane have been explicit on this point: boson sampling was not designed with industry use cases in mind. It is, as one Xanadu documentation entry put it, "just a quantum system being its best self."
A more pointed challenge comes from researchers at the University of Bristol and Imperial College London, whose 2022 paper in Science Advances demonstrated new classical simulation algorithms that reduced the time needed to replicate earlier Gaussian boson sampling experiments by nine orders of magnitude. The USTC team addressed this class of objection directly in the Nature paper, comparing Jiuzhang 4.0's output against the matrix product state (MPS) method—a recently proposed classical algorithm that exploits photon loss to reduce simulation difficulty—and concluding that the quantum advantage persists. Still, the pattern of classical algorithms narrowing each successive gap means the gap will continue to be tested.
The U.S.–China Economic and Security Review Commission stated in its November 2025 report that Chinese quantum breakthroughs "often lack independent verification", and a January 2026 analysis by the Center for Strategic and International Studies echoed that concern, noting that Chinese quantum systems "are reported to rival international competitors" but that "verification from a third party has not been done." Publication in Nature, a peer-reviewed journal, provides one layer of scrutiny, but external replication of Jiuzhang 4.0's results has not yet been reported.
Quantum Race Tightens as U.S. Export Controls Take Effect
The publication lands as Washington and Beijing have moved from research competition to active economic confrontation over quantum technology. President Biden's August 2023 executive order, and the Treasury Department's final rule that took effect January 2, 2025, prohibited U.S. persons from investing in Chinese quantum computer development. The U.S. Bureau of Industry and Security has imposed export controls on quantum processors with 34 or more fully controlled qubits and on the cryogenic cooling systems those superconducting processors require. The photonic architecture of Jiuzhang sidesteps that last restriction entirely: it needs no cryogenic hardware.
A Royal United Services Institute analysis published in 2025 warned that U.S. export controls, by severing Chinese access to foreign quantum components, are accelerating a self-sufficient Chinese quantum supply chain rather than slowing one. That dynamic is already visible: Jiuzhang 4.0's laser sources come from Shanghai Precilaser Technology, a domestic supplier that has separately exported laser sets to Harvard University. China's 15th Five-Year Plan, unveiled in March 2026, explicitly names quantum as a "future industry" and calls for expanded investment in scalable quantum computers and a space-to-earth quantum communication network.
Senators James Risch, Pete Ricketts, and Young Kim introduced the MATCH Act in April 2026, seeking to close gaps in semiconductor export controls and extend restrictions to Chinese quantum chip manufacturers including Origin Quantum and QuantumCTek. The bill's sponsors describe export controls on chipmaking tools as "the foundation of America's technology competition strategy with China."
What This Means for Encryption, and for You
The strategic stakes of quantum computing extend beyond laboratory benchmarks. Sufficiently powerful fault-tolerant quantum systems could break the public-key encryption that secures banking transactions, medical records, and government communications. The U.S. National Institute of Standards and Technology finalized its first post-quantum cryptography standards in August 2024, but adoption across critical infrastructure remains incomplete. Neither Jiuzhang 4.0 nor any other current system is close to the scale required to threaten those standards: all existing quantum hardware, including Jiuzhang 4.0, still operates in what researchers call the noisy intermediate-scale quantum (NISQ) era, where error rates constrain practical usefulness.
The near-term implications are more indirect. Quantum advantage demonstrations at this scale accelerate progress toward the fault-tolerant systems that could eventually render today's encryption vulnerable. Organizations that handle sensitive long-lived data—governments, hospitals, financial institutions—face a concrete decision: migrate now to post-quantum cryptographic standards, or wait and absorb the risk that adversaries are already harvesting encrypted data for future decryption, a strategy known in the intelligence community as "harvest now, decrypt later."
The Path to Fault Tolerance Remains Contested
Lu said the Jiuzhang 4.0 results open possibilities for constructing "trillion-qubit-mode three-dimensional cluster states"—a theoretical architecture for fault-tolerant quantum computing. The USTC team's stated trajectory points toward the long-sought milestone at which quantum systems can correct their own errors reliably enough for real-world computation. Google's Willow processor demonstrated below-threshold quantum error correction in December 2024 using a superconducting approach, a milestone China's superconducting systems have not yet publicly matched according to available technical disclosures.
Whether photonic systems or superconducting ones reach fault tolerance first is genuinely open. Photonic architectures carry the room-temperature advantage and, as Jiuzhang 4.0 shows, a credible path to scale. Superconducting systems lead on error correction and gate fidelity. The answer will determine which country's engineering choices—and which supply chains—sit at the foundation of the next era of computing.
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