What is the ultra smallest computer

Smallest data storage device in the world

Data stores are getting smaller and denser about every two years. This is the trend in the computer industry. Researchers from the Max Planck Society and the IT group IBM have tested how far this miniaturization can be carried out and built the smallest memory in the world in the process. Instead of making existing components smaller and smaller, the researchers took the opposite approach: "Starting with the smallest, the atom, we built data storage devices atom by atom," explains Andreas Heinrich, head of the IBM laboratory in Almaden, California.

One bit for twelve atoms

Just twelve atoms - two chains of six atoms each - are needed, says Sebastian Loth, one of the "inventors", to store a data bit - the smallest unit in computer technology - over a long period of time. For comparison: a modern hard drive needs more than a million atoms for this.

The new mini data storage device is so tiny that it cannot be seen with the naked eye or with a normal microscope. The memory can only be visualized with the help of a computer that "feels" the atoms. It looks like a height profile, explains Loth. The experimental physicist worked for IBM until September 2011. The company, says Loth, is investing an enormous amount in basic research. You know here how important it is in the long term. Then Loth moved to the CFEL (Center for Free-Electron Laser Science). The research center is a cooperation between the German Electron Synchrotron Desy, the Max Planck Society and the University of Hamburg and works closely with IBM.

Nano antiferromagnet with atomic precision

The highlight: antiferromagnets instead of ferromagnets

Already there, Loth worked with colleagues on a mini memory for data. At the end of 2010 they had the brilliant idea: Instead of the usual ferromagnets - materials that attract iron, nickel or cobalt like a refrigerator magnet - they tried an antiferromagnet - a material that does not exert any force on iron, nickel or cobalt.

The conventional ferromagnets that are used for computer hard drives have one disadvantage: in them, the magnetic axes of all atoms point in the same direction. This creates magnetic fields that surround each storage element and significantly disrupt neighboring storage elements. The elements can therefore only be placed on a storage medium at certain distances from one another.

Quite different with antiferromagnets: Here the atoms align themselves in all possible directions, there is no magnetic field and therefore no disturbance. Storage elements can therefore be packed as tightly as possible on the smallest of structures, explains Sebastian Loth and assures: "This new storage principle has the potential to revolutionize computer technology."

Big step for research

So far, all of this has been basic research, says Loth. But the principle of using antiferromagnets for data storage has already met with great approval. From now on it is necessary to adapt the research results in such a way that the mini-storage systems are suitable for everyday use. Because the twelve-atom memory is only stable at an ultra-cold temperature of -268 degrees Celsius. Sebastian Loth estimates that between 150 and 200 atoms per bit are necessary for the nano memory to function at room temperature.

"It will certainly be some time before antiferromagnetic data points are actually used," says IBM spokesman Hans-J├╝rgen Rehm. The result is still a big step for research. "It's like opening a new door into the next room." It is the very first step, but it works.

Author: Judith Hartl
Editor: Andreas Sten-Ziemons