Dutch researchers have discovered what may well be the fastest and most dense digital storage method by disturbing the direction of an atom's magnetic field. Although still in its early experimental stages, the technology already promises the potential for data storage devices reading and writing at the terahertz range or about 1,000 times faster than current technology.

In experiments performed on the particle accelerator BESSY II of Helmholtz-Zentrum Berlin, Dutch researchers have achieved ultrafast magnetic reversal of an atom's magnetic moment. Magnetic moments are a magnet's polar direction, the north and south poles. An atom's magnetic moment is seen as its position relative to each other whether they are aligned along similar or opposite poles. This positioning allows representation of "1" and "0" and hence be used for data storage.

The discovery of this phenomenon has major implications in the way digital storage is currently viewed especially in what is considered the physical limitation of magnetic data storage – how small can small be? While much higher data densities can be packed in substrates that can be written and read with optical devices, this does not provide the relative speed of access that magnetic media allows even at its present level.

Changing the alignment of atoms so that their positions can be used to express binary data involves overcoming a quantum mechanical effect called 'exchange interaction'. In magnetism, this is the fastest and strongest force and understanding it is what defines the speed at which magnetic storage units can be induced to switch poles or in the case of atoms, alignment. It takes less than a hundred femtoseconds to restore magnetic order if it has been disturbed. One femtosecond is a millionth of a billionth of a second.

Dutch researchers led by Ilie Radu along with collaborators in Berlin and York in England have published their results in Nature magazine. By proving that magnetic reversal can take place in femtosecond timeframes, researchers have seen the potential for ultra fast and ultra dense magnetic data storage systems.