Lorenzo Buffoni — Università degli Studi di Firenze #
Qubits together strong: preparation of large high-fidelity qubit registers via cooperative effects #
We present a method, dubbed “cooperative quantum information erasure” (CQIE),  which uses both cooperative and quantum effects to reset large registers of qubits. We discuss how to leverage cooperative effects to achieve better reset protocols and why it matters for quantum technologies. Indeed, 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 ortogonality catstrophe weherby even an extremely high individual reset fidelity $f$ results in modest global fidelities $F=f^N$ for sufficiently large number $N$ of qubits. We will then discuss the implementation of CQIE on a commercial quantum annealer which achieved exceptionally high values of the measured global fidelity for a register of 5612 qubits.