"So far, the RAM technology has been rapidly advancing, with memory modules becoming ever faster. However, this type of memory has one major limitation that cannot be overcome, namely its low energy efficiency," said Sergei Nikitov, deputy head of MIPT's section of solid state physics, radiophysics and applied information technologies.
"In this paper, we present the magnetoelectric memory cell. It will reduce bit-reading and -writing energy consumption by a factor of 10,000 or more."
A cell in the magnetoelectric memory – also known as MELRAM – consists of two components: a piezoelectric material and a layered structure characterised by a high magnetoelasticity. Because the structure is anisotropic, it can be magnetised along two directions, which correspond to the zero and one in the binary code.
According to the researchers, in contrast to dynamic RAM, magnetoelectric memory cells can maintain their state: they need not be continually rewritten and do not lose information when power is cut off.
"We built a test piece about 1mm across and showed that it works," explained MIPT PhD student Anton Churbanov. "It is worth noting that the structures we used could serve as the basis of nano-sized memory cells, whose dimensions are similar to those of regular RAM cells."
When a voltage is applied to the memory cell, the piezoelectric layer of the structure is deformed. Depending on the nature of the strain, magnetisation assumes a particular orientation, storing information. The changing orientation of the magnetic field gives rise to increased voltage in the sample. By detecting this voltage, the state of the memory cell can be determined.
The researchers believe their solution can be scaled down without any adverse effect on its efficiency, which makes MELRAM promising for computing hardware applications requiring low energy consumption.
