Imaging Josephson Vortices on Curved Junctions

Abstract

Understanding the nature of vortices in type-II superconductors is crucial for comprehending exotic superconductors and advancing the application of superconducting materials in future electronic devices. This study uses spectroscopic scanning tunneling microscopy to visualize Josephson vortices along crystalline domain boundaries in the superconducting spinel oxide LiTi2O4 (LTO). Our experimental results reveal that the local curvature of the Josephson junction dictates the positioning of Josephson vortices. Self-consistent solutions of the Bogoliubov-de Gennes and gap equations theoretically corroborate this observation. In addition to enhancing our understanding of the physics of Josephson vortex formation, this study offers potential guidelines for developing vortex-based superconducting devices.