In 2009, researchers at Rutgers University in Piscataway, New Jersey, demonstrated2 that the material has a photovoltaic response to visible light — meaning that when it is hit by light, a voltage is created. The size of the voltage depends on which polarization state the material is in, and can be read out using electrodes or transistors. Crucially, shining light on the material doesn’t change its polarization, and so does not erase the data stored in it.

via Computer memory can be read with a flash of light : Nature News & Comment.

It takes less than 10 nanoseconds to write to and read the cells, and recording the data requires about 3 volts. The leading nonvolatile RAM technology, flash, takes about 10,000 times longer to read and write, and needs 15 volts to record.