Japanese researchers claim ‘new transistor’
As conventional electronics reaches the limits of scaling, researchers have been looking for alternative approaches. One avenue of exploration has been with strongly correlated materials, whose electrons interact with each other to produce unusual properties.
One of these properties is triggered in phase transitions: by applying a small external voltage, a large change is seen in electric resistance. This mechanism is said to be akin to a switch and to have many potential applications.
Researchers at the Riken Advanced Science Institute in Japan say they have created a transistor that harnesses this property. The device uses an electric double layer to tune charge density on the surface of vanadium dioxide (VO2). The strong correlation of electrons and electron-lattice coupling in VO2 allows this surface charge to drive electrons within the bulk to delocalise, magnifying the change of electronic phase. The researchers say a potential of 1V is enough to switch the material from an insulator to a metal, with resistance decreasing by three orders of magnitude.
The switching mechanism is thought to be useful as a novel building block for ultra low power devices, non volatile memory and optical switches.
