We report on the preparation of a large quantum register of 5612 qubits, with the unprecedented high global fidelity of F≃0.9956. This was achieved by applying an improved cooperative quantum information erasure (CQIE) protocol [Buffoni, L. and Campisi, M., Quantum 7, 961 (2023)] to a programmable network of superconducting qubits featuring a high connectivity. At variance with the standard method based on the individual reset of each qubit in parallel, here the quantum register is treated as a whole, thus avoiding the well-known orthogonality catastrophe wehereby even an extremely high individual reset fidelity f results in vanishing global fidelities F=fN with growing number N of qubits.
@article{arxiv.2406.16706,
title = {Collective preparation of large quantum registers with high fidelity},
author = {Lorenzo Buffoni and Michele Campisi},
journal= {arXiv preprint arXiv:2406.16706},
year = {2024}
}