Group seminar at MPQ and Zoom: Measurement-free fault-tolerant quantum computing

Friederike Butt, RWTH Aachen University, Germany
Group seminar at MPQ lecture hall and Zoom
Tuesday, 30 June 2026, 09:00 am (CEST)

The ability to perform quantum error correction (QEC) and robust gate operations on encoded qubits is a key step toward practical demonstrations of quantum algorithms. Contemporary QEC schemes typically require mid-circuit measurements with feed-forward control, which are challenging for qubit control, often slow, and susceptible to relatively high error rates.
I present protocols for a measurement-free universal toolbox of fault-tolerant logical operations based on code switching between two- and three-dimensional color codes. I translate the paradigm of code switching into a fully measurement-free setting, where protocols are implemented using fully coherent yet fault-tolerant circuits that avoid feed-forward during algorithm execution [1]. Finally, I demonstrate that this measurement-free toolbox enables the execution of fault-tolerant quantum algorithms, exemplified by a realization of Grover’s search on encoded logical qubits [2].
[1]: F. Butt et al., Sci. Adv. 11, eadv2590 (2025)
[2]: F. Butt, I. Pogorelov et al., Nat Commun 17, 995 (2026)