Using oxygen as bits

The layered structure of tantalum oxide, multilayer graphene and platinum used for a new type of memory developed at Rice University. Credit: Rice University

Researchers are still looking for ways to store data in denser, cheaper and faster ways as more and more data are being produced.

At Rice University a team of researchers has found a way to use the displacement of oxygen atoms by an electric field as a way to store 0's and 1's.

Researchers have created a 250nm thick sandwich of multilayers of tantalium, tantalium oxyde, platinum and graphene (deposited on a silicon oxyde) that when subjected to an electric field cause the displacement of oxygen atoms. This displacement changes the electrical characteristics of the material from a ohmic device (where current can flow in both directions) to a Schottky junction, a diode (where current can flow in just one direction).  This creates a difference that can be associated to the values of 0s and 1s.

The architecture requires only two electrodes per circuit, whilst present silicon oxyde memories requires three electrodes, and this makes for denser storage and for an easier stacking in 3D architectures. In addition it requires 100 times less energy than conventional memories providing a further plus (heat dissipation in storage is not that important, as it is in mciroprocessors, since you, statistically, seldom access the same bit and there is no accumulation of heat that needs to be dissipated, but power consumption means cost and therefore is important).

The electrodes are made of platinum (see the figure) and by applying the voltage oxygen atoms migrate from the tantalium oxyde (a semiconductor) to the graphene layer, that acts as a barrier to both oxygen atoms on one side and platinum atoms on the other, leaving behind tantalium (a metal having ohmic characteristics). 

According to researchers this new kind of solid state memory should not be far from industrial manufacturing.

Author - Roberto Saracco

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