TY  - EJOUR
AU  - Zen, Remmy
AU  - Olle, Jan
AU  - Colmenarez, Luis
AU  - Puviani, Matteo
AU  - Müller, Markus
AU  - Marquardt, Florian
TI  - Quantum Circuit Discovery for Fault-Tolerant Logical State Preparation with Reinforcement Learning
IS  - arXiv:2402.17761
M1  - FZJ-2025-01550
M1  - arXiv:2402.17761
PY  - 2025
N1  - 34 pages, 20 figures
AB  - The realization of large-scale quantum computers requires not only quantum error correction (QEC) but also fault-tolerant operations to handle errors that propagate into harmful errors. Recently, flag-based protocols have been introduced that use ancillary qubits to flag harmful errors. However, there is no clear recipe for finding a fault-tolerant quantum circuit with flag-based protocols, especially when we consider hardware constraints, such as qubit connectivity and available gate set. In this work, we propose and explore reinforcement learning (RL) to automatically discover compact and hardware-adapted fault-tolerant quantum circuits. We show that in the task of fault-tolerant logical state preparation, RL discovers circuits with fewer gates and ancillary qubits than published results without and with hardware constraints of up to 15 physical qubits. Furthermore, RL allows for straightforward exploration of different qubit connectivities and the use of transfer learning to accelerate the discovery. More generally, our work opens the door towards the use of RL for the discovery of fault-tolerant quantum circuits for addressing tasks beyond state preparation, including magic state preparation, logical gate synthesis, or syndrome measurement.
LB  - PUB:(DE-HGF)25
UR  - https://juser.fz-juelich.de/record/1038567
ER  -