Scanning tunneling microscopy of superconductors and high field electron spin resonance

Abstract

Electron spin resonance on the single atom level is demonstrated with a scanning tunneling microscope (STM) in a frequency range from 60 to 100 GHz. For the irradiation of the high frequency signal, an external antenna has been built into the STM. Advanced methods for the signal's transfer function compensation have been developed. Furthermore, the multiband Josephson effect is analyzed for the type I two-band superconductor Pb for different tip-sample distances. The consideration of the interaction with the local electromagnetic environment and multiple Andreev reflections allows for the extraction of multiple microscopic parameters.