QuEra Launches Open-Source Package to Simulate Logical Quantum Circuits at Scale

Fast universal simulator for quantum error correction gives researchers and quantum software developers a powerful tool to design, test, and optimize the next generation of quantum computers.

BOSTON, April 2, 2026 /PRNewswire/ -- QuEra Computing today open-sourced its T-gate simulator (Tsim), a GPU-accelerated quantum circuit simulator that, for the first time, lets researchers simulate non-Clifford gate operations at the speed and scale that quantum error correction (QEC) development demands.

QEC is the essential bridge between today's noisy quantum processors and the fault-tolerant machines that will deliver practical quantum advantage. Designing effective QEC protocols — including surface code experiments, magic state distillation circuits, and logical gate sequences — requires simulating circuits at the physical level across millions of shots. Because a real fault-tolerant, commercially relevant quantum computer is still in development, the quality of these simulation tools directly shapes the pace of progress.

Yet today's toolkit has a critical gap. Non-Clifford gates, particularly T-gates, are what make quantum circuits universal: without them, quantum computations offer no speedup over classical computers. The most widely adopted QEC simulator, STIM, handles only Clifford gates. Other tools that support T-gates are limited in qubit count or are too slow for the statistical analysis that QEC research requires. Tsim closes that gap, supporting quantum circuits with 80+ physical qubits and producing millions of samples in parallel — approximately 600 nanoseconds per shot for an 85-qubit circuit on an NVIDIA GH200.

"We built Tsim for our own research and are releasing it because the entire QEC community benefits when researchers can simulate realistic fault-tolerant circuits quickly and at scale," said Shengtao Wang, VP of Algorithms and Applications at QuEra Computing. "By open-sourcing Tsim, QuEra has extended its fault-tolerant momentum from hardware into software, giving the research community tools to design and validate the protocols that those machines will run."

By enabling fast simulation of the gate operations that make quantum computing universal, Tsim gives researchers, quantum software developers, and hardware engineers worldwide a powerful tool to:

• Design more reliable quantum computers: Because physical qubits are extremely error-prone, scientists and engineers use error-correction to protect quantum information while testing different strategies and architectures in simulations.
• Test error-corrected algorithms before running them: Running experiments on error-corrected quantum hardware is often limited by availability and cost. Researchers simulate circuits first to determine whether an algorithm works and to estimate the resources required.
• Accelerate quantum research: Because Tsim can be accelerated using GPUs, simulations that previously took days or weeks can run much faster.
• Support training and education: Quantum computing students and researchers can use the tool to learn how advanced circuits behave.

Tsim is compatible with the STIM circuit format and API, so researchers can extend existing simulation pipelines to non-Clifford circuits with minimal effort. It is also part of QuEra's open-source Bloqade™  ecosystem, which provides a complete workflow from quantum program definition through compilation, noise modeling, simulation, and decoding.

The release extends a landmark year for QuEra's fault-tolerant program. In 2025, four Nature papers — produced in collaboration with, and in several cases led by, QuEra's academic partners at Harvard and MIT — demonstrated continuous operation of multi-thousand-atom arrays, integrated fault-tolerant architectures with up to 96 logical qubits, the first logical-level magic state distillation, and algorithmic fault tolerance that reduced runtime overhead by 10–100x for reconfigurable architectures such as neutral atoms.

QuEra will hold a Tsim webinar on April 28 at 1:00 PM EST. Register here.

Access Tsim on this GitHub repository. 

About QuEra Computing

QuEra is putting quantum to work. As the scientific and commercial leader in neutral-atom quantum computing, we help enterprise innovators leverage quantum to gain competitive advantage, support HPC centers as they help users tackle classically intractable problems, and enable government programs to build national capability and sovereign capabilities. We do this through our quantum innovation platform, combining quantum systems available on-premises and via the cloud with application co-design and collaborative research. Born at Harvard and MIT, still advancing together, QuEra operates globally from Boston, Tokyo, and the United Kingdom. As quantum computing moves from "one day" to "Day One," QuEra delivers practical impact today while advancing toward large-scale, fault-tolerant systems. See what's possible at quera.com.

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SOURCE QuEra Computing