Spectroscopy of spin-split Andreev levels in a quantum dot with superconducting leads
Abstract
We use a hybrid superconductor-semiconductor transmon device to perform spectroscopy of a quantum dot Josephson junction tuned to be in a spin-1/2 ground state with an unpaired quasiparticle. Due to spin-orbit coupling, we resolve two flux-sensitive branches in the transmon spectrum, depending on the spin of the quasi-particle. A finite magnetic field shifts the two branches in energy, favoring one spin state and resulting in the anomalous Josephson effect. We demonstrate the excitation of the direct spin-flip transition using all-electrical control. Manipulation and control of the spin-flip transition enable the future implementation of charging energy protected Andreev spin qubits.
Keywords
Cite
@article{arxiv.2208.09314,
title = {Spectroscopy of spin-split Andreev levels in a quantum dot with superconducting leads},
author = {Arno Bargerbos and Marta Pita-Vidal and Rok Žitko and Lukas J. Splitthoff and Lukas Grünhaupt and Jaap J. Wesdorp and Yu Liu and Leo P. Kouwenhoven and Ramón Aguado and Christian Kraglund Andersen and Angela Kou and Bernard van Heck},
journal= {arXiv preprint arXiv:2208.09314},
year = {2024}
}
Comments
Updated references. Main: 8 pages, 4 figures. Supplement: 19 pages, 13 figures