Discovered in 2019, the material known as nickelates has intrigued researchers for its potential to become a superconductor at elevated temperatures - a property that could significantly advance such fields as quantum science and energy transmission. However, it’s a very unstable material and difficult to work with. But the lab of Professor Charles Ahn has developed a method that could enhance superconductivity in these materials. The results are published in Nature Communications.
With their ability to conduct electricity with no resistance, superconductors are a key component to quantum computing, medical imaging, and a number of other fields. A group of copper-oxide compounds known as cuprates have long been central to the study of high-temperature superconductivity (“high temperature” is a relative term—they still need to be kept in very cold environments). Nickelates are especially exciting because they share some of cuprates’ key electronic features while offering a new platform for materials design and tuning.
Enter nickelates, a material with many similarities to cuprates, but with the potential to eventually become even more useful to scientists. Dung Vu, a postdoctoral associate who led the study, noted that synthesizing nickelate thin films is “notoriously difficult.” The Ahn lab is one of the few in the world with the ability to do so.
“Reaching that point took us months to years of process optimization, because nickelate films are highly unstable and even small deviations in growth conditions can destroy the clean structure needed for superconductivity,” he said.
But nickelates come with their own downsides. One major challenge is that the bound electron pairs responsible for superconductivity, known as Cooper pairs, can be relatively fragile in nickelates. This limits how well the superconducting state survives at higher temperatures or in strong magnetic fields.
How they solved it
The researchers discovered that when they doped the nickelates with a material known as europium, it “fundamentally changed how electrons conduct electricity in these materials, and it changed the superconducting properties in these materials.”
One of the major effects, Vu said, was that europium made superconductivity in nickelate much more robust, allowing it to persist under conditions that would normally weaken or destroy electron pairing. One of the problems with typical superconductors, Vu said, is that when a magnetic field is applied, it breaks apart the Cooper pairs. What makes the result especially intriguing is that europium ions appear to partially shield the superconducting electron pairs from the applied field, helping the superconducting state survive to much higher magnetic fields.
“In this project, I had the chance to bring our thin film samples to do experiments at some of the world’s strongest magnets,” he said. “Our experiments demonstrated that superconductivity in these thin films persists even in these extreme environments.”
Building off this work, Vu said the researchers want to apply high pressures and other approaches to improve the material’s critical temperatures. Also, they aim to map out the electron structure of the doped material, and get a better sense of why europium has the effects that it does on nickelates.
This story is a duplicate of the Yale Engineering news story of April 22, 2026. Please see below for a link to the original article plus other related links.