Memory cell switching technique with terahertz radiation could boost performance by 1,000 times

Scientists claim that technique could switch memory cells in a trillionth of a second

Scientists from Germany, the Netherlands and Russia claim to have developed a technique that could eventually provide a 1,000-times performance boost to computer memory.

The method is intended to increase the speed at which memory cells can be switched, which is done in current-generation memory technology using a magnetic field.

However, the researchers claimed that this could be done as much as 1,000 times faster using terahertz radiation.

Terahertz radiation consists of electromagnetic waves with the frequencies of 0.3THz and 3THz. This occupies a middle ground between microwaves and infrared light in the electromagnetic spectrum.

The researchers believe that using electromagnetic waves oscillating at terahertz frequencies should make it possible to switch memory cells in trillionths of a second.

"Our finding addresses the long-term technological ambition of a direct, high-speed manipulation of magnetic data bits by an electric field, which is achieved at terahertz frequencies in our experiment," said Dr Rostislav Mikhaylovskiy, leader of the project at Radboud University in the Netherlands.

Professor Rupert Huber, who led the study at the University of Regensburg in Germany, described it as "a milestone of photonics".

The work builds on the experiments at Radboud to switch magnets using light. Electrical switching is as fast, but more energy efficient.

"Here we use low-energy terahertz photons with their energies equal to that of spin and orbital excitations underlying magnetism. To date the light manipulation relied on the use of visible photons with energies of one electronvolt," said Mikhaylovskiy.

"That is more than 100 times larger than the intrinsic energy scale of magnetism, which measure one to 10 milli-electronvolts."

The new technique is explained in detail in the latest issue of the scientific journal Nature.

The fruits of recent experiments in terahertz radiation have been applied to airport scanning equipment to "T-ray" people for things they should not be carrying.

However, the scientists' experiments were very basic and it will be some time before they are able to apply the techniques to memory technology.

It is, though, a fertile area of research. Boffins at Harvard are experimenting with T-rays at room temperature, and MIT is developing a terahertz camera that can apparently read closed books.