Prof. Randall Victora and doctoral student Rizvi Ahmed, recently presented a technique for the simulation of a magnetic field in chromia (Cr₂O₃), a material that in the not too distant future, could form the key component of computer memory. The findings appear in the paper “A fully electric field driven scalable magnetoelectric switching element,” published in the journal Applied Physics Letters. Prof. Victora was interviewed by the American Institute of Physics about the new development.
A switching element made from chromia could be the answer to the problem of reducing the size of memory components while also increasing energy efficiency. While consumers have come to expect greater memory sizes in small devices as a matter of routine, semiconductor companies have had to slow down; the size of memory components is not going down as rapidly as they once did, and current designs display a marked reduction in energy efficiency.
To overcome these challenges, researchers are investigating the use of magnetic fields to store information, a move away from transistors and electric fields that are typically used in memory devices, to store and retrieve information. A promising version of such a magnetic device depends on the magnetoelectric effect to switch the magnetic properties of a devices. However, the challenge here is that currently such a device requires large electric and magnetic fields.
According to Prof. Victora, the use of chromia as a possible answer to this lies in the fact that it has shown better potential for scaling and with refinements, could possibly be sized down, and be more energy efficient. The authors have designed a device where the chromia is surrounded with magnetic material, thereby doing away with the need for an externally applied magnetic field for it to operate. The details of the technique are explained in the paper.
The authors intend to collaborate with other researchers familiar with chromia to fabricate and test the device. If all ends well, then the new chromia-based device stands to replace dynamic random access memory (DRAM), and this could be a revolutionary change in computer memory components. DRAM is what provides the fast memory that we are all used to in our devices, but it is energy inefficient and volatile. (You can blame its volatility when you lose an unsaved document when your computer crashes.) A chromia-based device however would be non-volatile. There are challenges yet to be overcome; the study’s authors point to chromia’s low heat tolerance. Currently, their modeling predicts that the device will stop functioning around 30 degrees celsius, and computers tend to run hotter than that. A possible solution the authors suggest is the introduction of other elements to optimize its functioning. So rein in your excitement just a dash. It might be a few years before such a memory device hits the market.
This research was supported by C-SPIN, one of six STARnet centers, a Semiconductor Research Corporation Program sponsored by MARCO and DARPA.