Single-Atom radio frequency fingerprinting
Precise investigation tools for analyzing and manipulating matter down to the scale of single atoms are the eyes, ears and fingers of nanoscience and -engineering. SARF takes these nano-analytical ""senses"" one next step beyond the present state of the art. SARF is breaking new grounds by enabling spectral fingerprinting of single atoms for elemental identification and intra-molecular chemical analytics with sub-nanometer spatial resolution and operating in vacuum- as well as liquid-phase environments. This presently impossible combination of analytical capabilities simultaneously in a single tool is highly desirable to many diverse fields of nanoscience and technology, where decisive functionality originates from single individual atoms and molecules (e.g. spintronics, sensors, catalysis, medicinal drug development, surface physics, biology, etc.). SARF realizes resonance spectroscopy at giga-Hertz frequencies combined with scanning tunneling microscopy for specific single-atom fingerprinting. Characteristic resonance signals are locally detectable by the probe tip as small changes of conductance that indeed enable elemental and chemical identification. SARF conceives and develops single-atom fingerprinting on a manifold of different systems including magnetic and nonmagnetic metals, semiconductors and, exemplarily, tetrapyrrole-based metal-organic functional molecules. If successful, SARF will provide a controlled, versatile, fast and readily applicable ""atom-by-atom"" matter analysis, where single atoms are selected and identified one by one in real time and space.