A molecular memory to dye for

NewScientist.com

August 16, 2003

If a bit of information could be stored in a molecule, a memory block the size of a sugar cube would store terabytes of data, hundreds of times more than can fit on a DVD.

The molecule illustrated above is the first to be toggled between the states that store 1s and 0s and remain stable during read-out. It consists of a molecular dye linked to a molecular switch. Green light switches the molecule to an "on" state by breaking open a ring of carbon atoms, violet switches it "off", and red reads the state by causing the dye to fluoresce. Because each operation uses a different coloour of light, there is no risk of changing the molecule's state by reading it. This is a problem in other molecules because it corrupts the data that is stored.

One plan is to address a group of molecules in three dimensions using two weak laser beams of each colour. The light will only be intense enough to read or write data where the beams cross.

The chemists who created this molecule were led by Peter Rentzepis at the University of California, Irvine. They are negotiating with Call/Recall, a company in San Diego, to make a memory device by embedding the molecules in plastic.