According to the scientists, current commercially-available magnetic memory devices require 1million atoms.
“We have opened up new possibilities for quantum nanoscience by controlling individual atoms precisely. This research may spur innovation in commercial storage media that will expand the possibilities of miniaturising data storage,” said Andreas Heinrich, Director of IBS.
In this study, researchers worked with a Scanning Tunnelling Microscope (STM), which has a tip that enables the user to view and move individual atoms, as well as to apply a pulse of electrical current.
They used this electric pulse to change the direction of magnetisation of individual holmium atoms. By doing that, the team could write a memory of either 1 or 0 and swap the two.
A quantum sensor designed by the team, consisting of an iron atom, was used to read the memory stored in the holmium atom. Using this technique, as well as tunnel magnetoresistance, the researchers saw that holmium maintains the same magnetic state stably over several hours.
Placing holmium atoms even 1nm apart did not impact their ability to store information individually. This was unexpected as it was thought the magnetic field from one atom would impact its neighbour.
In this way, the scientists could build a 2bit device with four possible types of memory: 1-1, 0-0, 1-0 and 0-1.
"There are no quantum mechanical effects between atoms of holmium. Now we want to know why," explained Heinrich.
