IBM Proves Concept of Storing Data on Single Atom

Hasan Ahmed - 1B Nanotechnology
Posted on: March 10, 2017

Yeah, you read the title right. Now don’t get excited just yet; it’s not like you can store all your hard drive data on it or something. It’s just a proof of concept. But I’m in nanotechnology engineering, so proof of concept to me is a very positive phrase with a lot of potential. Especially since it’s actually on a nano scale. So how did these researchers do it?

Previous attempts with working on atomic structures resulted in hard drives that could be created on a nanoscale, but no information could actually be stored. It would just be readable. On the other hand, today’s method uses a concept which stores atoms in a binary format, with 1s or 0s. Then the atoms could be read for their binary value. The question is, could we manipulate the atoms so that if we needed to change a 1 or 0 to the opposite value, could we? The answer is yes.

IBM researchers used a single Holmium atom (atomic number 67), which is set on top of magnesium oxide. This “single atom bit” represents “the ultimate limit of the classical approach to high density magnetic storage media.” This was the first single-atom bistable magnetic bit, as others were 3-12 atoms. As technology gets smaller and smaller, the impact it can have gets larger. According to the Nature publication of this discovery, this setup of Ho and MgO particles can retain information for a relatively long time (a few hours). Using tunnel magnetoresistance, which basically reads information on small scale structures, as well as a scanning tunneling microscope (STM), the team was able to inscribe data on the Ho atom and read it, confirming that it can actually have “1” or “0” values. This STM applies a voltage to the atom, which is able to change its magnetic spin as a result. Since the atom only has two spins (hence bistability), the tunnel magnetoresistance was able to confirm that this atom indeed stored data.

The researchers also tested putting two atoms of Ho beside each other, and confirmed that all possible combinations (00,01,10,11) could be formed. They further proved their results by putting the Ho beside an iron sensor atom. The iron can detect nearby magnetic fields, and by testing this next to the Ho, they confirmed that the Ho had two discrete states which corresponded to two magnetic orientations. This is pretty good, as it means you can line up a bunch of Ho atoms without them affecting each other to an extent which would manipulate or potentially corrupt your data. Then again, more research probably has to be done on this to be absolutely sure. But think about it. Does this work with other atoms? How long before we implement this into computing that’s consumer friendly? Will we ever have tiny USBs? Can this help robotics? I mean, I’m shaking up and down with excitement as I’m writing this.

Now unfortunately it is an experiment carried out under low temperatures, as it was tested at 4.3 K and can hold up to temperatures past 30 K. So is it realistic just yet? No. But again, proof of concept is just one step further into a world of ideas and innovation.