Enlarge / Two layers of one of the materials used in this work. (credit: The American Mineralogist Crystal Structure Database)
We seem to be on the cusp of a revolution in storage. Various technologies have been demonstrated that have speed approaching that of current RAM chips but can hold on to the memory when the power shuts off—all without the long-term degradation that flash experiences. Some of these, like phase-change memory and Intel’s Optane, have even made it to market. But, so far at least, issues with price and capacity have kept them from widespread adoption.
But that hasn’t discouraged researchers from continuing to look for the next greatest thing. In this week’s edition, a joint NIST-Purdue University team has used a material that can form atomically thin sheets to make a new form of resistance-based memory. This material can be written in nanoseconds and hold on to that memory without power. The memory appears to work via a fundamentally different mechanism from previous resistance-RAM technologies, but there’s a small hitch: we’re not actually sure how it works.
The persistence of memristors
There is a series of partly overlapping memory storage technologies that are based on changes in electrical resistance. These are sometimes termed ReRAM and can include memristors. The basic idea is that a material can hold a bit that is read based on whether the electrical resistance is high or whether electrons flow through like it was a metal. In some of these, the resistance can be set across a spectrum that can be divided up, potentially allowing a single piece of material to hold more than one bit.