Jahn

Jahn is a surname of German origin derived from the given name Johannes (John). It is found among German-speaking communities and has spread with German diaspora to various parts of the world. The name has appeared in historical records, biographies, and genealogical sources across a range of fields.

One of the most notable bearers is Hermann Arthur Jahn (1900–1979), a German-born chemist who, with Edward Teller, proposed the Jahn–Teller effect in 1937. The Jahn–Teller effect describes how certain molecular geometries distort to remove electronic degeneracy and lower the system’s energy. This concept has wide-reaching implications in inorganic chemistry and solid-state physics, helping explain distortions in transition-metal complexes and influencing interpretations of crystal structures and electronic states.

In broader usage, the surname Jahn is associated with individuals across science, arts, and public life in German-speaking regions and beyond. The name’s prominence in scientific history is chiefly linked to the Jahn–Teller effect, which remains a foundational concept in the understanding of molecular geometry and electronic structure.