Why did Gerd Binnig and Heinrich Rohrer receive the 1986 Nobel Prize in Physics?

Gerd Binnig and Heinrich Rohrer were awarded half of the 1986 Nobel Prize in Physics for their joint invention of the scanning tunneling microscope (STM).12

Developed at the IBM Research laboratory in Zurich, the STM provided a revolutionary method for creating direct images of the atomic structure of surfaces. The instrument operates based on the quantum mechanical phenomenon known as tunneling, where electrons pass between a sharp tungsten probe tip and a sample surface. Because the tunneling current is extremely sensitive to the distance between the tip and the surface, the instrument can maintain a constant gap while scanning, allowing it to map surface topography with such precision that individual atoms are clearly recognizable.132

This achievement opened a new era for surface science, enabling researchers to document the arrangement of atoms on various materials and study phenomena such as surface reconstruction and atomic diffusion.3