Majorana sweet spots in three-site Kitaev chains

Nonoverlapping Majorana states form the foundation of quantum devices based on topological superconductors. Artificial Kitaev chains have recently emerged as a promising platform for realizing well-localized Majoranas. In their minimal form, these chains host Majoranas at isolated sweet spots in parameter space, with experimental signatures already observed in short chains. Here, the authors investigate three-site Kitaev chains, identifying and classifying distinct sweet spots based on Majorana localization, and outline practical methods to distinguish them---an essential step toward future Majorana-based quantum devices.