QuEra has open-sourced its T-gate simulator (Tsim), a GPU-accelerated quantum circuit simulator, which the company says 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.
According to QuEra’s announcement, other tools that support T-gates are limited in qubit count or are too slow for the statistical analysis that QEC research requires, while the most widely adopted QEC simulator, STIM, handles only Clifford gates. The company says Tsim supports 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.”
Tsim aims to give researchers, quantum software developers, and hardware engineers worldwide a 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.
Access Tsim on Github.
