Scientists have achieved a first in studying lanthanum superhydrides, a class of materials that could help unlock superconductivity at much higher temperatures.
The dream of transmitting electricity without energy loss has driven decades of superconductivity research. Some of the most promising candidates yet are superhydrides, hydrogen-rich materials that, under immense pressures, have exhibited superconducting behavior at temperatures far higher than conventional superconductors.
Now, an international team including scientists from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) has achieved a key breakthrough in studying these materials, using nuclear magnetic resonance (NMR) spectroscopy to probe lanthanum superhydrides under extreme pressure for the first time.
Superconductors are materials that lose all electrical resistance below a critical temperature specific to each material. This allows electricity to move through them without energy loss. In most known superconductors, that transition happens below about 140 Kelvin (minus 133 degrees Celsius), meaning practical use requires demanding cooling systems. Because of this, scientists are searching for materials that can become superconducting at much higher temperatures.
Superhydrides are hydrogen-rich compounds in which a metal, such as lanthanum, sits inside a tightly packed hydrogen lattice. Under enormous pressure, similar to conditions found inside planets, these materials can develop unusual electronic properties and may show superconductivity close to room temperature. They currently hold the world record for the highest critical transition temperature at which signs of superconductivity have been observed.
To reach those conditions, researchers compress the samples in diamond anvil cells, squeezing them between two diamonds at pressures greater than one million atmospheres. The difficulty is that the samples are extremely small, so studying them demands exceptional experimental precision.
Magnetic superlenses on a microscale
The new work addresses that challenge with so-called Lenz lenses, tiny conductive ring structures that focus the high-frequency fields needed for nuclear magnetic resonance (NMR) spectroscopy directly into the sample volume. By concentrating and amplifying those fields, the lenses make NMR measurements possible under the extreme conditions inside a diamond anvil cell.
“We had to focus the high-frequency fields precisely where the sample is located between the diamond anvils, over an area of just a few tens of micrometers, which is smaller than the diameter of a human hair,” explains Dr. Florian Bärtl from the Dresden High Magnetic Field Laboratory (HLD) at HZDR. “With the use of Lenz lenses, we were able to amplify the high-frequency signal to such an extent that, for the first time, meaningful NMR data became accessible for superhydrides.” The measurements offer direct information about the materials at the atomic scale and help researchers understand them more clearly.
Highest magnetic fields as an additional stress test
The team had previously studied the same materials with pulsed high-field magnets at the HLD by measuring their electrical resistance. These magnetic fields act as a stress test for superconductors because they show the maximum field strengths at which the superconducting state can remain stable.
A full picture of this class of materials emerges only when both methods are used together: NMR studies under high pressure and resistance measurements in the strongest magnetic fields.
The research was carried out in close collaboration with high-pressure specialists from the Center for High Pressure Science & Technology Advanced Research (HPSTAR) in Beijing. “The collaboration with the HLD was crucial to our project,” says Dr. Dmitrii Semenok. “The high-field facilities available there and the expertise in high-frequency instrumentation provide ideal conditions for these experiments.”
In the long term, the researchers want to better understand the physical mechanisms behind superconductivity in hydrogen-rich materials. That knowledge could help guide the development of new materials for more energy-efficient technologies.
References:
“Transmission of Radio-Frequency Waves and Nuclear Magnetic Resonance in Lanthanum Superhydrides” by Dmitrii V. Semenok, Florian Bärtl, Di Zhou, Toni Helm, Sven Luther, Joachim Wosnitza, Ivan A. Troyan, Viktor V. Struzhkin and Hannes Kühne, 8 February 2026, Advanced Science.
DOI: 10.1002/advs.202520701
“Ternary Superhydrides Under Pressure of Anderson’s Theorem: Near-Record Superconductivity in (La, Sc)H12” by Dmitrii Vladimirovich Semenok, Ivan Alexandrovich Troyan, Di Zhou, Andrei Vladimirovich Sadakov, Kirill Sergeevich Pervakov, Oleg Alexandrovich Sobolevskiy, Anna Gennadievna Ivanova, Michele Galasso, Frederico Gil Alabarse, Wuhao Chen, Chuanying Xi, Toni Helm, Sven Luther, Vladimir Moiseevich Pudalov and Viktor Viktorovich Struzhkin, 31 July 2025, Advanced Functional Materials.
DOI: 10.1002/adfm.202504748
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