A Rice University team has proposed that a strip of graphene 10 atoms thick could serve as the basic storage element in a new form of memory. With individual bits smaller than 10 nm, the memory’s capacity would improve upon today’s state-of-the-art flash memory by a factor of five when comparing 2-D arrays. Moreover, two terminals rather than three would control the new switches, making it practical to further increase density by stacking sheets of the material into 3-D arrays, according to the researchers.

Graphene sports an on/off power ratio of 1 million-to-one, the team states, enabling much larger arrays than other nonvolatile technologies, such as phase-change memory. Finally, the researchers say they have tested the technology over 20,000 cycles with no degradation and found it to be immune to temperature over –75 to +200°C.

In separate work, researchers at the United Kingdom’s University of Nottingham are working on a form of memory that would employ as its basic element a carbon nanotube nested within another slightly larger carbon nanotube. Application of power would force the inner tube to telescope into and out of the larger one, alternately bringing it into and out of contact with an electrode. In an unpowered state, the van der Waals force would keep each inner tube in place to preserve the stored data.