Rohrer, Heinrich (1933- )

Swiss physicist who was awarded the Nobel Prize for Physics in 1986 for his involvement in the invention of the scanning tunnelling electron microscope (STM), an ultra-powerful microscope capable of imaging individual atoms. He shared the award with Ernst Ruska and Gerd Binnig.

The scanning tunnelling electron microscope produces a magnified image by using a tiny tungsten probe, with a tip so fine that it may consist of a single atom, which moves across a specimen. The probe tip moves so close to the specimen surface that electrons jump (or tunnel) across the gap between the tip and the surface. The magnitude of the electron flow (current) depends upon the distance from the tip to the surface, and so by measuring the current the contours of the surface can be determined. The contours can be used to form an image on a computer screen of the surface.

Rohrer was born in Buchs, St Gallen, Switzerland, and educated in Zürich. After two postgraduate years at Rutgers University, New Jersey, USA, he joined the IBM Zürich Research Laboratories at Rüschlikon, Switzerland in 1963. The first STM was built at IBM with Gerd Binnig in 1981.