Researchers develop memory with one bit per molecule

Scientists from different countries have developed magnetic memory that requires only one molecule, consisting of 51 atoms, to store a bit. Modern hard drives use three million magnetic atoms per bit.

The scientists constructed the molecule by placing a magnetic iron atom in the middle of fifty other atoms. These fifty atoms act as an organic shell around the iron atom, protecting the information. Due to this organic shell, the iron atom is not affected by the superparamagnetic effect. This effect means that bits become more magnetically unstable as they get smaller. If a bit becomes too small, the heat from the environment can already supply enough energy to ‘flip’ the magnetic direction of the material. The superparamagnetic limit at which this effect occurs determines the maximum data density of the storage technology.

In addition, the molecule has another interesting property. The magnetic direction of the iron atom is changed using an electrical pulse rather than a magnetic field. Under the influence of this pulse, the resistance of the molecule also changes. Therefore, the value of the bit can be read with a resistance measurement.