Nanowires could be used to significantly boost conventional RAM, resulting in computers that are ready the minute you turn them on, and don't lose data when the power fails, says a US researcher.
Dr Stuart Parkin, an IBM research fellow based in San Jose presents his research on "racetrack memory" this week at the International Conference on Nanoscience and Nanotechnology in Sydney.
"You would never have to save your data or reboot your computer," says Parkin.
Current computers use solid state RAM to process data, but store data as magnetised regions on a hard disk drive.
The problem is, says Parkin, while hard disks are relatively economical, they are slow and unreliable.
It takes time for the disk to rotate to a point where data can be read or written. This is one of the reasons why it can be slow for a computer to boot up, as it loads the software from the hard disk into the RAM.
The reading and writing gadget can also crash the disk causing catastrophic damage, and if the power fails, information in the RAM that has not been saved to the hard disk is lost.
Two in one
Parkin says racetrack memory would combine the low cost of a hard drive with the reliability and speed of RAM in a single solid-state device. The result is RAM that is 100 times larger than currently available.
All data would be stored instantaneously so it is not lost when power is removed from the computer, he says.
"We're going to replace both the storage and the memory, if we're successful, with this one technology," says Parkin.
"You will then have a homogeneous technology where you can store the data but you can also perform computations on the data because it's so fast and doesn't wear out like the cheap memories today, like flash [memory used in USB sticks]."
Parkin says racetrack memory would make computers, simpler, smaller, more reliable, and more energy efficient as well as giving them much faster access to stored data.
While conventional RAM uses a single layer of silicon, racetrack memory will use a three-dimensional system to store more information, says Parkin.
He says the magnetic hard disk is replaced by a forest of magnetic nanowires, each sitting on silicon chip, and each with its own reading and writing gadget.
Each nanowire has about 100 magnetic regions representing digital data.
Instead of having to mechanically rotate a disk, a magnetic region can be moved up or down the nanowires (racetracks) depending on whether it needs to be read.
The regions are moved using the latest developments in spintronics, which exploits a quantum property of electrons, called spin.
Electron spin can be either up or down, but when all the electron spins in a material are aligned, this generates magnetism.
Parkin says magnetically-encoded data can be moved up and down the nanowires using a current of electrons, whose spin are all in one direction.
About 10 years ago, Parkin invented the device that uses electron spin to "read" data on hard disc drives.
He says the device was very sensitive and enabled hard disc to be used to store 1000 times more information than was possible before.
Parkin is now involved in building a prototype racetrack memory device and hopes that it will be available in consumer products in 5 to 10 years.