First developed in the 1960s, phase-change materials (PCMs) can switch between two types of structures to achieve very different electrical states. This means they can start off in a crystalline structure that conducts electricity and allows a current to flow freely through them, before switching to a glassy structure that acts as an insulator instead, stopping the electrical current in its tracks. These materials can achieve this switch between conductor to insulator in mere billionths of a second.
A International team of researchers in University of Cambridge in the UK the Singapore A*STAR Data-Storage Institute and the Singapore University of Technology and Design has developed PCM-based processors for computers that are capable of processing information 500 and 1,000 times faster than today’s average laptop computer. And they do this while using less energy than silicon-based devices.
Today’s Computer, Laptop and Smartphones are currently using Silicon-based integrated circuits. Until now, if engineers wanted to make a faster computer, they would need to increase the number of logic devices that could fit in the machine, which means making each logic device tinier and tinier. But we’re now at the point where silicon-based logic devices can’t get much smaller.
“As demand for faster computers continues to increase, we are rapidly reaching the limits of silicon’s capabilities,” said one of the team Stephen Elliott from the University of Cambridge’s Department of Chemistry, in a press release.
Right now, the smallest silcon-based logic and memory devices are about 20 nanometres in size – so about 4,000 times thinner than a human hair – and are constructed in layers. “As the devices are made ever smaller in order to increase their numbers on a chip, eventually the gaps between the layers will get so small that electrons which are stored in certain regions of flash non-volatile memory devices will be able to tunnel out of the device, resulting in data loss,” the team reports. “PCM devices can overcome this size-scaling limit since they have been shown to function down to about two nanometres.”
“Ideally, we’d like information to be both generated and stored in the same place [in PCM devices],” said lead author Desmond Loke of the Singapore University of Technology and Design, in the press release. “Silicon is transient: the information is generated, passes through and has to be stored somewhere else. But using PCM logic devices, the information stays in the place where it is generated.”
The team now has to figure out how to integrate their new devices into a computer, but once they do that, we can expect faster computers that take up less space and energy than the computers we have right now.