Tiny Device Speeds up Memory While Saving Power

Purdue University, West Lafayette, Indiana

Smart objects are required to store and retrieve massive amounts of data quickly without consuming too much power. Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved functionality in a material called molybdenum ditelluride. The two-dimensional material stacks into multiple layers to build a memory cell.

Researchers have discovered a new functionality in a two-dimensional material that allows data to be stored and retrieved much faster on a computer chip, saving battery life. (Purdue University illustration)

Chipmakers have long needed better memory technologies to enable a growing network of smart devices. One of these next-generation possibilities is resistive random access memory (RRAM).

In RRAM, an electrical current is typically driven through a memory cell made up of stacked materials, creating a change in resistance that records data as 0s and 1s in memory. The sequence of 0s and 1s among memory cells identifies pieces of information that a computer reads to perform a function and then store into memory again.

A material would need to be robust enough for storing and retrieving data at least trillions of times, but materials currently used have been too unreliable; therefore, RRAM hasn't been available yet for widescale use on computer chips. Molybdenum ditelluride could potentially last through all those cycles. The material allows a system to switch more quickly between 0 and 1, potentially increasing the rate of storing and retrieving information. This is because when an electric field is applied to the cell, atoms are displaced by a tiny distance, resulting in a state of high resistance, noted as 0, or a state of low resistance, noted as 1, that can occur much faster than switching in conventional RRAM devices.

Because less power is needed for these resistive states to change, a battery could last longer. In a computer chip, each memory cell would be located at the intersection of wires, forming a memory array called cross-point RRAM.

Future work involves building a stacked memory cell that also incorporates the other main components of a computer chip: logic, which processes data, and interconnects, which are wires that transfer electrical signals.

For more information, contact Joerg Appenzeller at This email address is being protected from spambots. You need JavaScript enabled to view it.; 765-494-1076.