We demonstrate the Parity Architecture on quantum hardware, using the quantum Fourier transform (QFT) as a benchmark. As a result, a record performance in both fidelity and qubit count is achieved using quantum processors with a native CZ-based instruction set. On the IBM Heron r3 chip, a process fidelity of the QFT algorithm of F≈10−2 for N=50 qubits is achieved. The scaling of the speedup compared to previous swap-based methods is super-exponential O(exp(N2)). Furthermore, we show that the scaling can be improved further by including iSWAP gates in the instruction set.
@article{arxiv.2604.12465,
title = {Demonstrating Record Fidelity for the Quantum Fourier Transform},
author = {Philipp Aumann and Michael Fellner and David Alber and Max Cykiert and Christoph Fleckenstein and Roeland ter Hoeven and Leo Stenzel and Riccardo J. Valencia-Tortora and Wolfgang Lechner},
journal= {arXiv preprint arXiv:2604.12465},
year = {2026}
}