Superconductivity is an extremely interesting, and potentially extremely useful, physical phenomenon. It refers to a state in which current flows through a material without resistance, and therefore without any loss of energy or waste heat. As our civilization is increasingly run by electronic devices, the potential benefit is huge.

As physicists unravel the quantum physics of superconductivity, this allows them to potentially design new materials that can display superconductivity in useful settings. One recent study presents a small breakthrough in a specific type of superconducting material – Kagome metals. These are a class of ferromagnetic metal metamaterials with an interwoven structure that resembles the Japanese basket by the same name. This creates some specific quantum effects that are currently being researched for their technological uses, one of which is superconductivity.

One of the ways in which superconductivity arises is through what are known as Cooper pairs – two electrons that join together in a quantum state that distributes them like a wave throughout the material. Cooper pairs can therefore “travel” through a material without resistance. A recent study looks at the formation of Cooper pairs within Kagome metals, showing something surprising to physicists. Previously it was believes that Cooper pairs were evenly distributed within Kagome metals. The new study finds that the number of Cooper pairs in the star-point locations with the Kagome pattern can contain a variable number of Cooper pairs.

This was predicted in 2023 by Professor Ronny Thomale. His predictions have now been verified by direct observation, changing how physicists think about the superconducting potential of Kagome metals. You can read the study if you want to delve deeper into the details, but let’s talk a bit about the technological potential.

First, like other superconducting material, Kagome superconductors require extremely low temperature, -272 C. Cooper pair generally are a phenomenon that happens at very low temperatures, and much of the research into superconductivity has been searching for materials in which Cooper pairs form and superconductivity happens at higher temperatures. The current record (for ambient pressure) is a cuprate of mercury, barium, and calcium, at around 133 K (−140 °C). A big breakthrough happened in the 80s when a class of ceramics was discovered with superconducting temperature above that of liquid nitrogen. Liquid nitrogen is relatively cheap, allowing for the practical development of devices operating at this temperature (like the superconducting supercollider, and the magnets used in plasma research for fusion).

Another class of material becomes superconducting at high temperature but at super high pressures, making them completely impractical for actual use. This research is mostly about understanding superconductivity, not necessarily developing usable superconducting material. I of course have to wonder if the research with Kagome metals is similar – improving our understanding of the underlying physics, but not necessarily a pathway to usable materials. That remains to be seen.

Of course, the press release emphasizes the potential applications – because they always (or at least almost always) do that. That’s the formula with any new material science research – what’s the sci fi tech application. Then lead with that. So I take any such discussion with a grain of salt. Still, we can explore what potential applications would look like, and if not with this exact material, then something similar.

For Kagome metals, it seems applications would be limited to things that are physically small. I don’t think this is the material we will be making superconducting cables out of. In fact the current observations are only at the atomic scale, not the macroscopic scale. But they could be useful tiny electronic components, such as diodes. The obvious application would be in computers, including quantum computers.

The potential benefit of superconducting components in computers should not be underestimated. Increasingly we are building huge data centers for multiple applications, with artificial intelligence apps likely to significantly increase the need for hardware. These data centers use massive amounts of energy, measure on the scale of major industrialized nations, and increasing. They also generate a great deal of heat, and therefore have to spend more energy for cooling.

Now imagine a data center with computers that have mostly superconducting components, using a fraction of the energy and producing little waste heat. Even if you had to supercool the entire thing with liquid nitrogen temperatures, it would likely be worth it.

But of course, the higher temperature the superconductors, the more cost-effective and practical they are. If such a data center needed to be merely refrigerated, to -40 C for example, that would be relatively easy and cost effective. The ultimate goal of superconducting research, of course, is the “room temperature” (ambient pressure) superconductor. It’s not clear if this is even physically possible – right now we have no theory of how a room temperature superconductor would work, but no one has proven that they are impossible either. They remain theoretical. This is the real promise of superconducting research, even if the approach does not lead directly to a specific application. The more we understand about the quantum physics of superconducting, the better we will be able to design and research new materials at higher temperatures.

I don’t know if we will see superconducting Kagome metal-based technologies in the future. We may or may not. But at least we have added on more piece of the puzzle to our understanding of superconductivity.