Heinrich Rohrer

Abstract

Heinrich Rohrer, Heini to his friends, passed away in Wollerau, Switzerland, on 16 May 2013, three weeks short of his 80th birthday. He has been called the father of nanotechnology, and he helped establish the field with the invention, along with Gerd Binnig and Christoph Gerber, of the scanning tunneling microscope (STM). For their work, Heini and Binnig shared half the 1986 Nobel Prize in Physics. The other half went to Ernst Ruska for the much earlier invention of the electron microscope. Heinrich Rohrer AIP/ESVA, PT COLLECTION, W. F. MEGGERS GALLERY OF NOBEL LAUREATESPPT|High resolutionHeini inspired many of us to get into nanotechnology. Perhaps most important, he guided the nascent field with his extraordinary wisdom. I remember him telling a group of us working on scanning probe microscopy that we could praise our own inventions to the high heavens, but that the trouble starts if we bad-mouth someone else’s inventions! In particular, he advised us to stay away from comparisons of our new scanning probe microscopes (SPMs) with electron microscopes. He said the problem is the temptation to compare our new, state-of-the-art instrument to an existing commercial one that may be using 20-year-old technology rather than what’s state of the art in that field.To those of us entering nanotech, Heini gave advice freely and provided substantial assistance. He helped the biophysics lab at the University of California, Santa Barbara, get started by sending it his first STM postdoc, Othmar Marti, for a year at the expense of IBM, Heini’s employer. He strongly encouraged innovation and the development of other SPMs. He frequently noted that as long as an SPM was different enough from existing ones, a use would be found for it. That has proved true: For example, even though scanning capacitance microscopes and scanning ion conductance microscopes have very poor resolution compared with the STM, they are useful because they are sensitive to things beyond topography.Heini was born on 6 June 1933 in the small town of Buchs in Switzerland. He studied physics at ETH Zürich, where he was an undergraduate under Wolfgang Pauli and Paul Scherrer. He stayed on to obtain his PhD, on the length changes of superconductors at the magnetic-field-induced superconducting transition, with Jørgen Lykke Olsen. As Heini wrote in his Nobel Prize biography, “Following in [Olsen’s] footsteps, I lost all respect for angstroms. The mechanical transducers were very vibration sensitive, and I learned to work after midnight, when the town was asleep.” That was important background for the invention of the STM, since measuring small distances in the presence of vibrations is crucial.In the summer of 1963, Ambros Speiser, director of the newly founded IBM Research Laboratory in Rüschlikon, Switzerland, invited Heini to join the physics effort there. Heini first worked on Kondo systems with magnetoresistance in pulsed magnetic fields and then on other magnetic systems. The real excitement started in 1978 when he hired Binnig, a genius who soon began work on what would become the STM. Heini had the good sense to give Binnig the freedom he needed to explore an area that was new to them both and totally unproven.Later Heini had the foresight to foster the transition of STM technology beyond IBM into the world. At first it seemed to many others that it would be impossible to enter that area. After all, the creative minds working at IBM had a budget in the millions for making complex devices that depended on magnetic levitation in ultrahigh vacuum at cryogenic temperatures. What academic researcher could hope to compete? But Heini was persistent in encouraging others to join the field. And, as it turned out, useful STMs could be made without magnetic levitation, without ultrahigh vacuum, and at room temperature.Although STMs in ultrahigh vacuum at cryogenic temperatures continue to give spectacular results, other SPMs have proved useful for technological and medical research in air or fluids at room temperature. The rapid and friendly spread of the technology is due in large part to the spirit of the field established by Heini: collaboration, cooperation, and mutual respect.© 2013 American Institute of Physics.