Hybrid ferromagnetic transmon qubit: Circuit design, feasibility, and detection protocols for magnetic fluctuations
Halima Giovanna Ahmad, Valentina Brosco, Alessandro Miano, Luigi Di Palma, M. Arzeo, Domenico Montemurro, Procolo Lucignano, Giovanni Piero Pepe, F. Tafuri, Rosario Fazio, D. Massarotti
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.