Zeeman-driven parity transitions in an Andreev quantum dot

Abstract

The Andreev spectrum of a quantum dot embedded in a hybrid semiconductor-superconductor interferometer can be modulated by electrostatic gating, magnetic flux through the interferometer, and Zeeman splitting from in-plane magnetic field. We demonstrate parity transitions in the embedded quantum dot system, and show that the Zeeman-driven transition is accompanied by a 0-π transition in the superconducting phase across the dot. We further demonstrate that flux through the interferometer modulates both dot parity and 0-π transitions.