Life’s smallest boundaries. As incredible as the constantly shrinking world of our electronic gadgets may seem to be we are fast approaching the next major boundary, the atomic boundary. Data storage, just as with all other technology is approaching this hard wall. As Clint Eastwood once said ‘A man has to know his limitations’, especially if you wish to invent ways around these same limitations.

A team of IBM scientists led by Andreas Heinrich – IBM Research Almaden, California – are preparing for this next barrier. Their work has led to the invention of a memory storage technology that may be able to use as little as a dozen iron atoms to store information. Not quite at the next sub-atomic level but instead a step closer, maybe the final step before we push past this next limitation.

“The chip industry will continue its pursuit of incremental scaling in semiconductor technology but, as components continue to shrink, the march continues to the inevitable end point: the atom. We’re taking the opposite approach and starting with the smallest unit — single atoms — to build computing devices one atom at a time.” said Andreas Heinrich, the lead investigator into atomic storage at IBM Research Almaden, in California.

As with most great discoveries this one is based on making use of an observed characteristic or property to achieve your goal. Just as electricity grew from the observations of electrical charges and their behaviour. In this case Iron atoms were seen to exhibit a strange magnetic behaviour in small groups. Iron atoms will always try to maintain a neutral or zero magnetic field – antiferromagnetic property -. This is very different from the magnetic properties used in by hard drives. A hard drive uses millions of atoms to generate a collective magnetic field, with all of the atoms sharing the same magnetic state – ferromagnetic property – and working collective to create a strong magnetic field that can be easily read or written to.

IBM’s new memory uses groups of twelve Iron atoms arranged on a sheet of copper – substrate -. The dozen atoms are arranged in two rows of six, a six by two array. Like the chequered pattern of a chess board the neighbouring iron atoms will always want to be the opposite to their neighbour, magnetic polarity not colour in this case – antiferromagnetic property -. So if the primary – top left – atom has a positive magnetic charge its neighbours will be negative, their neighbours positive and so on. Flipping the polarity of this primary iron atom will cause the surrounding atoms to alter their magnetic state.

Heinrich found that 12 atoms was the minimum number of atoms required to hold the magnetic pattern reliably, with enough strength. Using any less atoms causes quantum effects that will reduce the probability of them staying in the state that you left them. Using more atoms allows the state to be held for longer, more reliably and with-standing higher temperatures but takes up more space. The current system requires extreme cooling reliably operate, taking the device down to near absolute zero – −273.15 °C –.

The main tool used to construct and operate this new memory is the Scanning Tunneling Microscope – STM – that is used to arrange and switch the bits and bytes. The STM was also an IBM invention, created in IBM’s R&D labs in 1981. In 1989 they used it to manipulate atoms to spell out IBM using atoms, hard to read maybe but impressive at the time. The STM is a device that is able to use a stream of single electrons to observe and manipulate at the atomic level.

Heinrich demonstrated the technique by reading and writing the letters that make up the word THINK – an IBM corporate catch cry – using 96 iron atoms. The 96 atoms were harnessed to form a byte, a fundamental storage element of the digital world. Each byte requires 8 bits, with each bit requiring 12 iron atoms, hence the 96 atoms. A byte is defined as a collection of 8 bits that can represent numbers ranging from 0 to 255. Just enough to hold the ASCII character set which represents all letters, numbers and punctuation as a number, 0 to 255. The researchers were able to use the STM to write and read the letters THINK to the byte one letter at a time, demonstrating the two main functions required by a working memory system, the ability to write and store, then read and recover data.

This is a memory revolution not just an evolutionary technology. Starting from scratch, staring at a clean slate is a gutsy approach and pure IBM. There is still much work to be done to produce a cheap and reliable product from these new discoveries, this is just the beginning for this new and interesting technology. IBM has held the top spot amongst companies that create and patent technology, a spot they have held every year for the past 19 years. Last year alone they were granted 6,180 U.S. patents, at a cost of over 6 billion US dollars mind you. This is how we scale the walls of our limitations – human inventiveness – and this alone ensures the march of technology into the future.