Press releases
Please quote Nature Materials as the source of these items.
October 2004
Time for a memory upgrade
As our dependence on computers, electronics and other gadgets grows, so does our need for bigger memories, faster performance and smaller devices. Two papers in the December issue of Nature Materials, reported by Parkin and co-workers at IBM and Yuasa and co-workers at AIST, demonstrate that the next generation of magnetic storage cells might leave the laboratory sooner than we had thought possible.
This promising new technology for the commercialization of magnetic random-access memory (MRAM) is based on a magnetic tunnel junction — a sandwich constructed from two magnetic layers separated by a non-magnetic insulating barrier material. Normally, the electrons within the magnetic layers stay within their two-dimensional world, but due to quantum-mechanical effects, they can tunnel through the barrier to the other magnetic layer, depending on the relative alignment of the magnetic layers. Until recently, this electron current was mostly a low-temperature phenomenon. The groups of Parkin and Yuasa were able to grow thin films of these magnetic tunnel junctions, whose crystalline order allows large tunnelling currents to flow even at room temperature. This current tells us the magnetic state of a storage cell, so the tunnel junction acts as a sensor.
Because information is coded magnetically rather than electrically, the information remains even when the power is switched off, so future computers with MRAM won't suffer any boot-up time, and will potentially run faster and store more information for less money.
