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, researchers said.
    
A team at Cornell University led by postdoctoral associate John Heron has made a breakthrough in that direction with a room-temperature magnetoelectric memory device.
    
Equivalent to one computer bit, it exhibits the holy grail of next-generation nonvolatile memory: magnetic switchability, in two steps, with nothing but an electric field.
    
"The advantage here is low energy consumption," Heron said.
    
"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," said Heron.
    
Researchers made their device out of a compound called bismuth ferrite, a favourite among materials mavens for a spectacularly rare trait.
    
It is both magnetic - like a fridge magnet, it has its own, permanent local magnetic field - and also ferroelectric, meaning it is always electrically polarised, and that polarisation can be switched by applying an electric field.
    
Paper co-author Ramamoorthy Ramesh, Heron's PhD adviser at University of California, Berkeley, first showed in 2003 that bismuth ferrite can be grown as extremely thin films and can exhibit enhanced properties compared to bulk counterparts, igniting its relevance for next-generation electronics.
    
Because it is multiferroic, bismuth ferrite can be used for nonvolatile memory devices with relatively simple geometries.
    
The best part is it works at room temperature, researchers said. The study was published in the journal Nature.