Hybrid ferromagnetic transmon qubit: Circuit design, feasibility, and detection protocols for magnetic fluctuations

Year: 2022

Authors: Ahmad H.G., Brosco V., Miano A., Di Palma L., Arzeo M., Montemurro D., Lucignano P., Pepe G.P., Tafuri F., Fazio R., Massarotti D.

Autors Affiliation: Univ Napoli Federico II Monte S Angelo, Dipartimento Fis Ettore Pancini, I-80126 Naples, Italy. Seeqc, Str Vicinale Cupa Cinthia 21, I-80126 Naples, Italy. CNR, SPIN, UOS Napoli, Via Cinthia, I-80126 Naples, Italy. Univ Roma La Sapienza, Natl Res Council, Inst Complex Syst, Ple A Moro 2, I-00185 Rome, Italy. Univ Roma La Sapienza, Dipartimento Fis, Ple A Moro 2, I-00185 Rome, Italy. Res Ctr Enrico Fermi, Via Panisperna 89a, I-00184 Rome, Italy. CNR Ist Nazl Ott CNR INO, Largo Enrico Fermi 6, I-50125 Florence, Italy. Abdus Salam Int Ctr Theoret Phys, Str Costiera 11, I-34151 Trieste, Italy. Univ Napoli Federico II, Dipartimento Ingn Elettr & Tecnol Informaz, Via Claudio, I-80125 Naples, Italy. Yale Univ, Dept Appl Phys, New Haven, CT 06520 USA

Abstract: We propose to exploit currently available tunnel ferromagnetic Josephson junctions to realize a hybrid superconducting qubit. We show that the characteristic hysteretic behavior of the ferromagnetic barrier provides an alternative and intrinsically digital tuning of the qubit frequency by means of magnetic field pulses. To illustrate functionalities and limitation of the device, we discuss the coupling to a readout resonator and the effect of magnetic fluctuations. The possibility to use the qubit as a noise detector and its relevance to investigate the subtle interplay of magnetism and superconductivity is envisaged.

Journal/Review: PHYSICAL REVIEW B

Volume: 105 (21)      Pages from: 214522  to:

More Information: The work has been supported by the project ?EffQul- Efficient integration of hybrid quantum devices?-Ricerca di Ateneo Linea A, CUP: E59C20001010005 and the project ?SQUAD-On-chip control and advanced read-out for super-conducting qubit arrays,? Programma STAR PLUS 2020, Finanziamento della Ricerca di Ateneo, University of Napoli Federico II CUP E65F22000390005. This work was also co-funded by European Union-PON Ricerca e Innovazione 2014-2020 FESR/FSC-Project ARS01_00734 QUANCOM. D. Mo. has been supported by PON R&I 2014-2020 ?AIM: Attraction and International Mobility? Linea 1 ?Mobilita dei ricercatori? CUP E66C19000060001. H.G.A., D.M., D.Mo., and F.T. gratefully acknowledge the NANOCOHYBRI project (COST Action CA 16218) . The authors also thank Mark G. Blamire and Avradeep Pal for useful discussions. The authors declare that they have no conflict of interest.
KeyWords: SUPERCONDUCTING, QUBITS, NOISE
DOI: 10.1103/PhysRevB.105.214522