University of Rochester scientists have developed a new form of computing memory that is fast, dense, and low-power.
The new computing memory was created by the team by strategically straining materials that are as thin as single layers of atoms.
In the study published in Nature Electronics, ‘Strain engineering of vertical molybdenum ditelluride phase-change memristors,’ the researchers outline their hybrid resistive switches.
Combining the best qualities of existing forms of computing memory
Developed by Stephen M Wu, assistant professor of electrical and computer engineering and of physics, the new approach marries the best qualities of two existing forms of resistive switches used for memory – memristors and phase-change materials.
They have been explored for their benefits over the most prevalent forms of computing memory, such as dynamic random-access memory and flash memory.
However, both resistive switches have drawbacks.
Problems with resistive switches
Memristors operate by applying voltage to a thin filament between two electrodes. They suffer from a relative lack of reliability compared to other forms of computing memory.
On the other hand, phase-change materials involve selectively melting a material into either an amorphous or crystalline state. These require too much power.
Wu said: “We’ve combined the idea of a memristor and a phase-change device in a way that can go beyond the limitations of either device.
“We’re making a two-terminal memristor device, which drives one type of crystal to another type of crystal phase. Those two crystal phases have different resistance that you can then story as memory.”
Leveraging 2D materials
The team used 2D materials that can be strained to the point where they lie between two different crystal phases. At this point, they can be nudged in either direction with little power.
“We engineered it by essentially just stretching the material in one direction and compressing it in another,” said Wu.
“By doing that, you enhance the performance by orders of magnitude. I see a path where this could end up in home computers as a form of memory that’s ultra-fast and ultra-efficient. That could have big implications for computing in general.”
How to strain the material
The team partnered with researchers from Rochester’s Department of Mechanical Engineering, including assistant professors Hesam Askari and Sobhit Singh, to understand where and how to strain the material.
Wu believes that the biggest hurdle to making the new computing memory is to improve the overall reliability.
However, the team are encouraged by the progress made so far.
