When Marianne Tarun was a Washington State University (WSU) doctoral student, she made an accidental discovery of a 400-fold increase in the electrical conductivity of a crystal simply by exposing it to light.
The effect, which lasted for days after the light was turned off, could dramatically improve the performance of devices like computer chips, according to WSU News.
Tarun noticed that the conductivity of some strontium titanate shot up after it was left out one day under room light exposure and room temperature.
The Filipino scientist shared how the team at first didn’t realize the increased conductivity was due to the light exposure, thinking that the sample was contaminated. A series of experiments proved that the light in fact was the cause of the increased crystal conductivity.
“One very remarkable implication of this…is the holographic memory where we could write and read data optically,” said the Filipino physicist in a video report made in 2013 when the discovery was made.
Matthew McCluskey, Tarun’s co-author of the paper and chair of WSU's physics department, explained, "The discovery of this effect at room temperature opens up new possibilities for practical devices. In standard computer memory, information is stored on the surface of a computer chip or hard drive. A device using persistent photoconductivity, however, could store information throughout the entire volume of a crystal. This approach, called holographic memory, could lead to huge increases in information capacity," McCluskey said.
What Tarun and the WSU team foresaw in 2013, is now followed through by the University of Southampton in UK which in 2016 developed the 5D “Superman Memory Crystal” using laser light to store unlimited data for millions of years.
Tarun, an Ateneo de Manila University Physics masters degree holder and graduate of Philippine Normal University, is continuing her work with semi conductors and teaching Physics as a post doctoral fellow at Simon Fraser University.