Few minutes with Peter Gruenberg, the Father of Spintronics

As an electrical engineer, the talk that interested I was interested in most most was the one by Peter Gruenberg, the 2007 Nobel Laureate in Physics, since his discovery of giant magnetoresistance (GMR) revolutionized the computer memory technology within just ten years and has led to exponential increase in the capacity of memory devices to the terra byte regime. GMR effect happens to be the basis of read heads of modern hard disk drives and nonvolatile magnetic random access memory (MRAM). GMR based memory is considered as the st commercial product of nanotechnology.

Gruenberg's talk began at 9.30 am on July 1. At the age of 69, senility has taken much of his physical strength, but his talk attested that his mind is still very active. In his slow speech, he described his inventions in a chronological order. Beginning with his 1986 invention of inter-layer exchange coupling and 1987 discovery of GMR, he briey described the concepts of current-in-plane (CIP) GMR, current-parallel-plane (CPP) GMR and tunneling magnetoresistance (TMR). In the conclusion he explained how these inventions led to the revolution in computer applications and upheld the vision of engineering the spin properties of materials enabling spintronics.

On the 4th of July, I had an opportunity of have an intimate discussion with Prof. Gruenberg. As soon as, he heard that I am an electrical engineer, he reminisced that after graduating as physicist he thought of studying electrical engineering. But as it required time and effort to bridge between these two different elds, he did not go forward in that direction. Although his research is mainly application oriented, he finds enjoyment in doing theoretical research. To him, experimental research and applications are inherently tied to the advancement of science. As he expressed his own ideas of the role of technology in developing countries, he gave the examples of solar energy technology, cellular communication technology having impact on the developing
countries. He also mentioned the research on these technologies at Juelich Research Lab, where he belongs to.

I finish this section with a popular hearsay about him. At Juelich, the only instances of his locomotion are seen when he goes in and out of the lab in the morning and evening respectively. All the other times, he sit sill in his table and occasionally looks down under his table in search of something mysterious.