Molecular memory is electric

Researchers from Osaka Kyoiku University in Japan have found a way to use a single molecule to store computer information.

Computer memory devices must have at least two states in order to represent the 1s and 0s of binary information, and there must be some way to sense and switch between states in order to read and write information.

The researchers' photochromatic diarylethene molecule contains a ring that switches between an open and a closed shape when voltage causes a negatively charged electron and positively charged hole to combine. A lower voltage does not switch the molecule but can sense the difference in electrical resistance of the two states, and thus read the molecule.

Because the researchers' molecule can be read and written to using electricity, it is potentially compatible with existing electronics. It also works at room temperature and has the potential to draw very little power.

The molecular memory could be used to store very large amounts of information in small areas, and also as inexpensive disposable memory, according to the researchers.

It is theoretically possible to use single electrons to change the molecules' states, meaning memory made from the molecules would consume little power.

Inexpensive disposable memory circuits could become practical into three years. Ultra-high density molecular memory systems could become practical in five to ten years, according to the researchers. The work appeared in the August 4, 2003 issue of Applied Physics Letters.