Few-site implementations of the Kitaev chain offer a minimal platform to study the emergence and stability of Majorana bound states. Here, we realize two- and three-site chains in semiconducting quantum dots coupled via superconductors, and tune them to the sweet spot where zero-energy Majorana modes appear at the chain ends. We demonstrate control of the superconducting phase through both magnetic field and sweet-spot selection, and fully characterize the excitation spectrum under local and global perturbations. All spectral features are identified using the ideal Kitaev chain model. To assess Majorana localization, we couple the system to an additional quantum dot. The absence of energy splitting at the sweet spot confirms the high quality of the Majorana modes, despite the minimal size of the chains.
@article{arxiv.2504.13702,
title = {Probing Majorana localization of a phase-controlled three-site Kitaev chain with an additional quantum dot},
author = {Alberto Bordin and Florian J. Bennebroek Evertsz' and Bart Roovers and Juan D. Torres Luna and Wietze D. Huisman and Francesco Zatelli and Grzegorz P. Mazur and Sebastiaan L. D. ten Haaf and Ghada Badawy and Erik P. A. M. Bakkers and Chun-Xiao Liu and Ruben Seoane Souto and Nick van Loo and Leo P. Kouwenhoven},
journal= {arXiv preprint arXiv:2504.13702},
year = {2025}
}