idw – Informationsdienst Wissenschaft
Nachrichten, Termine, Experten
Nachrichten, Termine, Experten
Various methods are used to correct errors in quantum computers. Not all operations can be implemented equally well with different correction codes. Therefore, a research team from the University of Innsbruck, together with a team from RWTH Aachen and Forschungszentrum Jülich, has developed a method and implemented it experimentally for the first time, with which a quantum computer can switch back and forth between two correction codes and thus perform all computing operations protected against errors.
Computers also make mistakes. These are usually suppressed by technical measures or detected and corrected during the calculation. In quantum computers, this involves some effort, as no copy can be made of an unknown quantum state. This means that the state cannot be saved multiple times during the calculation and an error cannot be detected by comparing these copies. Inspired by classical computer science, quantum physics has developed a different method in which the quantum information is distributed across several entangled quantum bits and stored redundantly in this way. How this is done is defined in so-called correction codes. In 2022, a team led by Thomas Monz from the Department of Experimental Physics at the University of Innsbruck and Markus Müller from the Department of Quantum Information at RWTH Aachen and the Peter Grünberg Institute at Forschungszentrum Jülich in Germany implemented a universal set of operations on fault-tolerant quantum bits, demonstrating how an algorithm can be programmed on a quantum computer so that errors can be corrected efficiently. However, different quantum error correction codes also come with different difficulties. A theorem states that no correction code can implement all the gate operations required for freely programmable computations with the logical quantum bits easily and protected against errors.
Quantum gates are realized with different correction codes
To circumvent this difficulty, Markus Müller's research group has established a method that allows the quantum computer to switch back and forth between two correction codes in an error-tolerant manner. “In this way, the quantum computer can switch to the second code whenever a logic gate that is difficult to realize appears in the first code. This makes it easier to implement all the gates required for computing,” explains Friederike Butt, a doctoral student in Markus Müller's research group. She developed the quantum circuits on which the experiment is based and implemented them in close collaboration with Thomas Monz's research group in Innsbruck. “Together, we have succeeded for the first time in realizing a universal set of quantum gates on an ion trap quantum computer using two combined quantum error correction codes,” says PhD student Ivan Pogorelov from the Innsbruck research group.
“This result is based on our many years of good collaboration with Markus Müller's team,” says Thomas Monz, who knows the theoretical physicist from his doctoral studies at the University of Innsbruck.
The findings of the current study were published in the journal Nature Physics. The research was financially supported among others by the Austrian Science Fund FWF, the Austrian Research Promotion Agency FFG, the German DFG, the Bavarian State Government, the European Union and the Federation of Austrian Industries Tyrol.
Thomas Monz
Department of Experimental Physics
University of Innsbruck
+43 512 507 52452
thomas.monz@uibk.ac.at
https://www.quantumoptics.at/
Markus Müller
Department of Quantum Information
RWTH Aachen
Peter Grünberg Institute 2
Forschungszentrum Jülich
+49 241 80 28412
m.mueller@physik.rwth-aachen.de
https://www.quantuminfo.physik.rwth-aachen.de/
Experimental fault-tolerant code switching. Ivan Pogorelov, Friederike Butt, Lukas Postler, Christian D. Marciniak, Philipp Schindler, Markus Müller, and Thomas Monz. Nature Physics 2025. DOI: 10.1038/s41567-024-02727-2 [arXiv: https://arxiv.org/pdf/2403.13732]
https://www.uibk.ac.at/en/newsroom/2022/error-free-quantum-computing-gets-real/ - Error-Free Quantum Computing Gets Real
Calculating error-free more easily with two codes
Helene Hainzer
Helene Hainzer
Merkmale dieser Pressemitteilung:
Journalisten, jedermann
Informationstechnik, Physik / Astronomie
überregional
Forschungsergebnisse, Wissenschaftliche Publikationen
Englisch
Calculating error-free more easily with two codes
Helene Hainzer
Helene Hainzer
Sie können Suchbegriffe mit und, oder und / oder nicht verknüpfen, z. B. Philo nicht logie.
Verknüpfungen können Sie mit Klammern voneinander trennen, z. B. (Philo nicht logie) oder (Psycho und logie).
Zusammenhängende Worte werden als Wortgruppe gesucht, wenn Sie sie in Anführungsstriche setzen, z. B. „Bundesrepublik Deutschland“.
Die Erweiterte Suche können Sie auch nutzen, ohne Suchbegriffe einzugeben. Sie orientiert sich dann an den Kriterien, die Sie ausgewählt haben (z. B. nach dem Land oder dem Sachgebiet).
Haben Sie in einer Kategorie kein Kriterium ausgewählt, wird die gesamte Kategorie durchsucht (z.B. alle Sachgebiete oder alle Länder).
