Instant-start computers in offing

New York: What if you can start your computer instantly with the click of a mouse? Researchers at Cornell University are making this happen with a new device. To encode data, today's computer memory technology uses electric currents - a major limiting factor for reliability and shrinkability and the source of significant power consumption.

If data could instead be encoded without current - for example, by an electric field applied across an insulator - it would require much less energy and make things like low-power, instant-on computing a ubiquitous reality. Now, postdoctoral associate John Heron and professor of physics Dan Ralph have made a breakthrough in that direction with a room-temperature magneto-electric memory device.

Equivalent to one computer bit, it exhibits the holy grail of next-generation non volatile memory - magnetic switchability in two steps with nothing but an electric field. "The advantage here is low energy consumption. It requires a low voltage, without current, to switch it. Devices that use currents consume more energy and dissipate a significant amount of that energy in the form of heat. That is what's heating up your computer and draining your batteries," Heron explained.

The researchers made their device out of a compound called bismuth ferrite, a favourite among materials mavens for a spectacularly rare trait: It's both magnetic - like a fridge magnet, it has its own, permanent local magnetic field - and also ferroelectric, meaning it's always electrically polarised.

Because it is multiferroic, bismuth ferrite can be used for non volatile memory devices with relatively simple geometries. The best part is it works at room temperature. The results were published online in the journal Nature.