Have you ever felt your smartphone heat up after heavy use or watched the battery drop at the worst possible moment? A big reason is the electronic circuits and memory inside the device, which consume energy and release heat as they operate.
At the most basic level, computer memory stores information as 0s and 1s by controlling how easily electricity can pass through a material. If scientists can design memory that requires far less electricity, it could dramatically reduce the energy demands of phones, computers, and other electronics.
A New Approach to Low Power Memory
One idea aimed at solving this problem dates back to 1971, when researchers proposed the ferroelectric tunnel junction (FTJ). This type of memory depends on ferroelectricity, a property in which a material’s internal electric polarization can be switched. When this polarization changes, it affects how easily current flows, allowing the device to store data.
Despite its promise, traditional materials used for this type of memory struggled as devices were scaled down. Performance often dropped as components became smaller, limiting how far the technology could go.
Hafnium Oxide Enables Ultra Small Memory
A key advance came in 2011, when scientists discovered that hafnium oxide, a widely used material, could retain its electric polarization even when extremely thin. Building on this finding, Professor Yutaka Majima and his team at the Institute of Science Tokyo (Science Tokyo) set out to develop an extremely small memory device measuring just 25 nanometers across, roughly one three-thousandth the thickness of a human hair.
Solving Leakage at the Nanoscale
Shrinking memory to this scale introduces a major challenge. Electrical current tends to leak through the boundaries between tiny crystals in the material, which has long prevented further miniaturization.
Instead of trying to avoid this issue, the researchers took a different approach. They made the device even smaller, which reduced the impact of those crystal boundaries.
They also developed a new fabrication method by heating the electrodes so they naturally formed a semicircular shape. This design created a structure closer to a single crystal, meaning there were fewer boundaries where leakage could occur.
A Breakthrough Where Smaller Means Better
By combining this structural design with extreme miniaturization, the team achieved high performance in their device. More importantly, they demonstrated something unexpected. The memory actually performs better as it becomes smaller, overturning a long-held assumption in electronics.
What This Means for Future Devices
If this technology is brought into real-world use, it could have wide-reaching effects. Devices like smartwatches could run for months on a single charge, and networks of connected sensors might operate without needing frequent battery replacements.
In artificial intelligence (AI), this type of memory could support faster processing while using far less energy. Because hafnium oxide is already compatible with existing semiconductor manufacturing, integrating this new memory into everyday electronics could happen relatively quickly.
Comment from the researcher
Challenging what seem to be the limits of science — such as ‘we cannot make things any smaller’ or ‘they will break if we do’ — is like walking in the dark. It is a continuous struggle. However, by questioning traditional assumptions and exploring new ways to overcome these barriers, we were able to discover an entirely new perspective. I would be delighted if this achievement sparks the curiosity of young people who will shape the future and helps build a better world. — Yutaka Majima, Professor, Materials and Structures Laboratory, Institute of Integrated Research, Institute of Science Tokyo.