IBM researchers at the Almaden and École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland created the world’s smallest magnet and data storage medium. It consists of a single iron atom attached to the tip of a scanning tunneling microscope. This design creates an electron-spin resonance sensor that can detect the magnetic field of an atom.
The scientists tested the new magnet on holmium atoms. With the new sensor, the magnetic poles of the holmium atoms are detectable and they can be manipulated. The significance is that data can be stored on the atom similarly to how data is stored on a hard disk (1 and 0).
Researchers were able to place the iron atom within a nanometer of the holmium atom and read the north and south pole.
The scanning tunneling microscope introduces a current to the holmium atom and flips the north/south pole. This changes it from 1 to 0 or 0 to 1. This resembles the ‘write’ process in hard drives. The ‘read’ process involves the iron atom detecting the magnetic state of the holmium atom.
According to IEEE, a credit card sized device with this storage medium would be able to store the entire iTunes library, which consists of 35 million songs.