Blueprint for a Molecular-Spin Quantum Processor

• DOI: 10.1103/physrevapplied.19.064060
• Publication Date: 2023-06-21T14:47:03Z
• Authors: A. Chiesa; S. Roca; S. Chicco; M.C. de Ory; A. Gómez-León; A. Gomez; D. Zueco; F. Luis; S. Carretta
• Keywords: Quantum Physics; Condensed Matter - Materials Science; Settore PHYS-03/A - Fisica sperimentale della materia e applicazioni; Quantum physics; 500; Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences; Physics - Materials science; 7. Clean energy; 530; modelli; metodi matematici e applicazioni; Settore PHYS-04/A - Fisica teorica della materia; Quantum Physics (quant-ph)

16 pages, 11 figures. Accepted in Physical Review Applied<br/>The implementation of a universal quantum processor still poses fundamental issues related to error mitigation and correction, which demand to investigate also platforms and computing schemes alternative to the main stream. A possibility is offered by employing multi-level logical units (qudits), naturally provided by molecular spins. Here we present the blueprint of a Molecular Spin Quantum Processor consisting of single Molecular Nanomagnets, acting as qudits, placed within superconducting resonators adapted to the size and interactions of these molecules to achieve a strong single spin to photon coupling. We show how to implement a universal set of gates in such a platform and to readout the final qudit state. Single-qudit unitaries (potentially embedding multiple qubits) are implemented by fast classical drives, while a novel scheme is introduced to obtain two-qubit gates via resonant photon exchange. The latter is compared to the dispersive approach, finding in general a significant improvement. The performance of the platform is assessed by realistic numerical simulations of gate sequences, such as Deutsch-Josza and quantum simulation algorithms. The very good results demonstrate the feasibility of the molecular route towards a universal quantum processor.<br/>