Sascha Heußen

Quantum Error Correction • Fault-Tolerant Circuit Design • Near-Term Quantum Computers

About Me

I am a postdoc-level research scientist. My interests are in small-scale fault tolerance and near-term implementations of quantum error correction. This matters because ultra-high-fidelity qubits are needed to practically implement quantum algorithms that are actually useful and cannot be simulated on classical computers. My current affiliation is with neQxt [nɛkst], an ion-trap quantum computing company. I am based in Cologne, Germany.

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Join the team

At neQxt, our theory team explores the principles that make scalable quantum computing possible. We focus on quantum error correction, fault-tolerant circuit design, and the development of logical qubit algorithms, providing both a foundation for experiment and a space for advancing pure theory.

Quantum error correction is at the heart of our work. By designing and analyzing codes, decoding methods, and logical gate constructions, we seek to understand how to preserve fragile quantum information over long timescales. We also study the design of fault-tolerant circuits and the behavior of noise in quantum systems. Developing new simulation techniques and software tools allows us to probe the limits of computation under realistic conditions while testing architectures that may guide near-term implementations.

Beyond the direct link to hardware, we keep an eye on the bigger picture. Fundamental questions about error thresholds, efficient decoding, and scalable architectures are central to our efforts. This balance of practical and conceptual work ensures that our research contributes not only to the neQxt quantum processors, but also to the broader understanding of quantum fault tolerance.

Our team is a place where theory meets practice and where curiosity-driven research thrives. Whether tackling immediate challenges of quantum processor design or venturing into abstract questions about codes and complexity, the theory group at neQxt provides a conceptual backbone for reliable and scalable quantum computing.

Projects

Here is a complete list of publications and preprints

  • Heußen, S., & Hilder, J. (2025). Efficient fault-tolerant code switching via one-way transversal CNOT gates. Quantum, 9, 1846. https://doi.org/10.22331/q-2025-09-03-1846
  • Hilder, J., Heußen, S., Ginter, A., Wilke, A., Poschinger, U., Schmidt-Kaler, F., & Wormsbecher, W. (2025). Quantum Internet in a Nutshell — Advancing Quantum Communication with Ion Traps. arXiv preprint arXiv:2507.14383.
  • Heußen, S. (2025). Magic state distillation without measurements and post-selection. arXiv preprint arXiv:2504.17509.
  • Postler, L., Butt, F., Pogorelov, I., Marciniak, C. D., Heußen, S., Blatt, R., Schindler, P., Rispler, M., Müller, M., & Monz, T. (2024). Demonstration of fault-tolerant Steane quantum error correction. PRX Quantum, 5(3), 030326. https://doi.org/10.1103/PRXQuantum.5.030326
  • Heußen, S., Winter, D., Rispler, M., & Müller, M. (2024). Dynamical subset sampling of quantum error-correcting protocols. Physical Review Research, 6(1), 013177. https://doi.org/10.1103/PhysRevResearch.6.013177
  • Heußen, S., Locher, D. F., & Müller, M. (2024). Measurement-free fault-tolerant quantum error correction in near-term devices. PRX Quantum, 5(1), 010333. https://doi.org/10.1103/PRXQuantum.5.010333
  • Butt, F., Heußen, S., Rispler, M., & Müller, M. (2024). Fault-tolerant code-switching protocols for near-term quantum processors. PRX Quantum, 5(2), 020345. https://doi.org/10.1103/PRXQuantum.5.020345
  • Heußen, S., Postler, L., Rispler, M., Pogorelov, I., Marciniak, C. D., Monz, T., Schindler, P., & Müller, M. (2023). Strategies for a practical advantage of fault-tolerant circuit design in noisy trapped-ion quantum computers. Physical Review A, 107(4), 042422. https://doi.org/10.1103/PhysRevA.107.042422
  • Postler, L., Heußen, S., Pogorelov, I., Rispler, M., Feldker, T., Meth, M., Marciniak, C. D., Stricker, R., Ringbauer, M., Blatt, R., et al. (2022). Demonstration of fault-tolerant universal quantum gate operations. Nature, 605(7911), 675–680. https://doi.org/10.1038/s41586-022-04721-1
  • Heußen, S., White, C. D., & Refael, G. (2021). Extracting many-body localization lengths with an imaginary vector potential. Physical Review B, 103(6), 064201. https://doi.org/10.1103/PhysRevB.103.064201

Contact

Email: s.heussen@neqxt.org

Publication list on Google Scholar

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