Nobel Prize for Physics Scientific explanation

Prof. Asa Auerbach from the Faculty of Physics at the Technion explains that this is a basic development of an application to a physical phenomenon that was known but had no use before

Prof. Asa Auerbach, from the Faculty of Physics at the Technion, a solid state theoretician and an expert in the field of condensed matter theory and, among other things, also deals with the conduction properties and magnetic properties of materials, says in a conversation with the website the scientist that all hard disks over 2 gigabytes, that is, all disks sold today, contain a reader Based on GMR. "Until the discovery of the GMR, coils that read magnetic fields were used for the reading heads of the hard disks. It is very difficult to produce and especially difficult to minimize these heads. All the uses of the GMR effect are in the field of computers, where apart from hard disks, the phenomenon allows non-destructive reading of RAM memories.

How does the system work, from the physical point of view?"They artificially created a resistor whose electrical resistance can be adjusted - will it make electrical conduction difficult or facilitate it, by controlling the direction of the magnetic field of the conductor slices (for example iron) located in the resistor. If each layer is magnetized in the opposite direction, the resistor will make it harder for the electrons to move The resistor will make it easier for the electrons to move and will be a better conductor. The difference in resistance between the two situations, in the materials developed by the two winners, is greater than in natural materials (such as iron) that were previously used to read data. Another important fact that emerges from the research is that the effect allows us to sense weak magnetic fields and by changing the resistance we can discover a very weak magnetic field like the one used to store data, which is its main use.

To what extent can the heads and with them the hard disks be minimized?"The size of the component is measured at about 100 nanometers, it will be possible to produce reading heads with the size of micron particles. The problem is that this is only a component of the reading, but the barrier to reducing the size of the disk heads is at the head of the writing, where a different technology is used that is difficult to minimize."

According to Prof. Auerbach, this is a development that was based on a known physical phenomenon, but it had no application until then. Like the MRI, whose developers won a Nobel Prize a few years ago, although the phenomenon has been known for decades, but as soon as an application is found for it, in the case of the MRI a medical application and in this case - an application in the computing revolution, this deserves a Nobel Prize.