An international team of researchers has described a new physical effect that could be used to develop more efficient magnetic chips for information processing. The quantum mechanical effect makes it easier to produce spin-polarized currents necessary for the switching of magnetically stored information. The research findings were published online on 28 July in the high-impact journal Nature Nanotechnology.
Random-access memory is the short-term memory in computers. It buffers the programs and files currently in use in electronic form, in numerous tiny capacitors. As capacitors discharge over time, they have to be recharged regularly to ensure that no data are lost. This costs time and energy, and an unplanned power failure can result in data being lost for good.
Magnetic Random Access Memories (MRAMs), on the other hand, store information in tiny magnetic areas. This is a fast process that functions without a continuous power supply. In spite of this, MRAMs have yet to be implemented on a large scale, as their integration density is still too low, and they use too much energy, are difficult to produce, and cost too much.
One reason for this is that spin-polarized currents, or spin currents for short, are needed to switch the magnetic areas of the MRAMs. Spin is the intrinsic angular momentum of electrons that gives materials their magnetic properties, and it can point in two directions. Spin currents are electric currents that possess only one of these two spin types. Similar to the way in which the Earth’s magnetic field affects the needle of a compass, a current of one of the spin types influences a magnetic layer and can cause it to flip.
Read more at: Phys.org