WHY THIS MATTERS IN BRIEF
The amount of information society is creating every day is leaving today’s storage technologies creaking at the seams, and our only option is to go smaller.
The building blocks of today’s modern computers have been getting progressively smaller ever since they were first invented, but now, as we create and design new 1nm scale transistors and computers that are smaller than viruses, and harness quantum mechanics to create next generation quantum computers, IBM have managed to go one better. They’ve managed to store one bit of data on one atom.
For now though the advance might be more symbolic than practical because of the complexity, and cost involved of commercialising the technology, but it’s a great way to show what the future holds for storage, and it’s another example of science fiction turning into science fact – along with deflector shields, laser weapons, tractor beams and replicators.
Atoms are the smallest unit of matter, and to put this into perspective this week researchers managed to store a movie, and several other things, on the nucleotides of DNA – a record in its own right – which are made up of thirty atoms, and a few months ago researchers managed to cram 10 bits onto a photon – yes, a photon! Meanwhile today’s state of the art solid state drives can hold a single bit of information in 100,000 atoms, which all in all means that IBM’s latest announcement trumps them all – by a very wide margin.
IBM’s breakthrough involved a single Holmium atom – a large atom that has lots of unpaired electrons – that was set on a bed of magnesium oxide. In this configuration, the atom has what’s called magnetic bistability, in other words, it has two stable magnetic states each with different spins.
The researchers used a scanning tunnelling microscope to apply 150 millivolts at 10 microamps to the atom, and while that doesn’t sound like a lot when you’re an atom that’s like being hit by lightening. This huge influx of electrons caused the Holmium atom to switch its magnetic spin state, and because the two states have different conductivity profiles, the microscope’s tip managed to detect which state the atom was in by applying a lower voltage, about 80 millivolts, and sensing its resistance.
In order to be absolutely sure though that the atom was changing its magnetic state, and thereby “holding data,” and that this wasn’t just some random interference the researchers laid it next to an iron atom. Iron atoms are affected by their local “magnetic neighbourhoods” and the iron atom acted differently to the Holmium atom when probed, which proved the experiment truly created a lasting, stored magnetic state in a single atom that can be detected indirectly.
And bingo – there you have it. One bit. One atom. One record.