Novel designs of Josephson weak links based on semiconducting nanowires combined with circuit QED techniques have enabled the resolution of their fine structure due to spin-orbit interactions, opening a path towards Andreev spin qubits. Nevertheless, direct manipulation of the spin within a given Andreev state is in general suppressed compared to inter-doublet manipulation in the absence of Zeeman effects. In addition, noisy spin-flip mechanisms limit any coherent manipulation protocol to spin post-selection. We propose a combination of a spin polarization protocol analogous to sideband cooling with stimulated Raman adiabatic passage specifically tailored for these systems. We show this approach is robust for a large range of design parameters, including the currently rather stringent coherence times.
@article{arxiv.2012.07132,
title = {Spin Coherent Manipulation in Josephson Weak Links},
author = {Javier Cerrillo and Max Hays and Valla Fatemi and Alfredo Levy Yeyati},
journal= {arXiv preprint arXiv:2012.07132},
year = {2021}
}