Qedma and HQC2 Improve Quantum Chemistry Accuracy With Error Mitigation

Insider Brief

• Qedma and the HQC2 team at the University of Copenhagen, Technical University of Denmark and University of Southern Denmark demonstrated improved accuracy in a quantum chemistry calculation using Qedma’s QESEM error mitigation software.
• The study used an orbital-optimized variational ansatz to calculate the potential energy surface of a water molecule on IBM’s Aachen quantum processor.
• Researchers reported a 30–50× improvement over raw results without error mitigation, showing how error mitigation can improve quantum chemistry calculations on noisy quantum hardware.

PRESS RELEASE — Qedma Quantum Computing, a pioneer in quantum error reduction software, together with the HQC² team at University of Copenhagen (KU), Denmark, Technical University of Denmark (DTU) and University of Southern Denmark (SDU), today published the findings of a collaborative study that delivered accurate quantum chemistry results, demonstrating the value of error mitigation in quantum computation. Qedma‘s researchers will be presenting this work and a separate talk on quantum advantage at Q2B Copenhagen, September 9-10, 2026.

In the study, researchers at HQC² and Qedma explored the potential energy surface of a water molecule using an orbital-optimized variational ansatz on IBM’s Aachen quantum processor with Qedma’s QESEM error reduction software. Led by Prof. Stephan P. A. Sauer and postdoctoral researcher Renato Olarte Hernandez at University of Copenhagen (KU), together with Prof. Sonia Coriani and postdoctoral researcher Emanuele Rossi at the Technical University of Denmark (DTU), the study was carried out as part of Q-CHEMION, a project under the Eureka open call for applied quantum technologies.

The research achieved exceptionally high accuracy for quantum computation, a 30–50× improvement over the raw results achieved without QESEM error mitigation.

Today’s quantum processors are noisy, which can make quantum chemistry calculations unreliable and inaccurate. QESEM mitigates the impact of noise in current quantum computers. Rather than waiting for large-scale, fully fault-tolerant quantum computers, QESEM’s patented approach unlocks the ability to execute larger and more complex quantum workloads while producing accurate results. It is currently being used by leading enterprises, academic institutions, and research laboratories around the world.

“We’re extremely pleased with the results of this collaborative study that clearly illustrates how our error mitigation software can help bridge the gap between today’s noisy quantum devices and the high-accuracy quantum computations required for future scientific applications,” said Qedma CEO and Co-founder Dr. Asif Sinay. “The work shows a strong proof of concept for applying quantum computing to quantum chemistry on current hardware, demonstrating improved accuracy as higher levels of precision were required.”

“Accuracy is particularly important in quantum chemistry, where even relatively small errors can affect the reliability of calculated molecular properties and energies,” said Prof. Stephan P. A. Sauer, KU. “This study allowed us to explore how error mitigation can improve the accuracy of chemistry calculations performed on today’s noisy quantum hardware. The results demonstrate the potential of approaches such as QESEM to help achieve the high levels of precision required for quantum chemistry applications.”

Qedma recently demonstrated quantum advantage together with IBM, accurately resolving the dynamics of quantum materials unseen in classical simulation. The results marked the first time quantum advantage has been achieved with commercially available hardware and software, reaching a paradigm where multiple state-of-the-art classical approaches failed to provide consistent, reliable answers.

Qedma Presentations at Q2B Copenhagen

• Quantum Advantage: Modeling Physics Beyond Classical Capabilities by Eyal Leviatan, Qedma, together with Prof. Stephan P. A. Sauer, KU, at 12:10 on September 9, 2026
• Water Potential Energy Surface Study on a Quantum Computer with QESEM’s High-Accuracy Error Mitigation by Renato Olarte Hernandez, KU, together with Tali Shnaider, Qedma, at 16:10 on September 10, 2026