Researchers hunting for the “Holy Grail” of superconducting materials that can achieve zero energy loss at relatively high temperatures and normal pressures are reportedly excited at the prospect of a new class of promising candidates known as Nickelates.
Although previous efforts to create true superconductivity, where no energy is lost in transmission, have been marred by controversy, including the rare unpublishing of a paper by the prestigious journal Nature in November 2023, the researchers exploring this new family of materials believe they may finally be on the right track.
The Storied Search for Superconducting Materials
Since the first practical experiments with electricity by 19th-century scientists and hobbyists, modern engineers have been searching for ways to reduce the amount of power lost in transmission. In the early 20th century, Nikola Tesla’s alternating current (AC) ultimately surpassed the industry standard direct current (DC) due to its simplicity and significant power savings. Nonetheless, virtually all electronic wires and devices still lose at least some energy in transmission.
In recent decades, researchers have begun exploring potential superconducting materials that can essentially eliminate energy transmission loss. While some successes have been measured, the top candidates typically require extremely high pressures or extremely low temperatures to operate. These narrow operating conditions have dramatically limited their potential applications.
One promising candidate for a potential room temperature superconductor that supposedly showed no energy loss at 21 Degrees C (70 F) briefly energized the field in 2023. As noted, Nature decided to take the study down after several failed attempts to replicate the work. Many of the study’s authors also said the final paper did “not accurately reflect the provenance of the investigated materials, the experimental measurements undertaken, and the data-processing protocols applied.”
To unravel the very nature of superconducting materials, researchers are exploring the potential quantum nature of light to understand “strange metals” that can act as superconducting materials. Another research group is studying a quantum vortex that appears to form within some superconducting materials to see if the key to this phenomenon lies within the quantum realm.
More recently, scientists have explored several promising routes to creating superconducting materials. One approach involves twisting stacked layers of two-dimensional graphene to achieve what engineers call the “Magic Angle.” Another study demonstrated the unique properties of this magic angle by stopping light in its tracks. A third research effort connected the idea of magic angle superconductivity to the infamous double-slit experiment that demonstrates light behaving as both a particle and a wave. So far, none of these efforts have resulted in a true high-temperature superconductor.
“Key Hallmarks” of Superconductivity in Nickelates
In this latest effort, physicists from the Southern University of Science and Technology (SUSTech) in Shenzhen, China, explored the relatively high temperature (45 kelvin or –228 C) and low-pressure superconductivity potential of compounds containing nickel. According to the researchers, the team observed “the key hallmarks” of superconductivity within a thin film of laboratory-grown nickel oxide crystals.
If correct, this discovery would place nickelates alongside two groups of ceramics described as “unconventional superconductors” that can maintain zero energy loss transmission at normal pressures and temperatures as high as 150K (-123 C). When describing the work, Lilia Boeri, a physicist at the Sapienza University of Rome, said perhaps the most “exciting” breakthrough by the Chinese team is “the idea that you have a system that you can sort of tune experimentally” to explore the limits of unconventional superconductivity.
The researchers concede that Nickelates “have a long way to go” before their superconductivity temperature matches other unconventional superconducting materials like copper-based cuprates or iron-based pnictides. However, the ability to tune the material’s properties means they could ultimately be tuned to work at even higher temperatures. Danfeng Li, a physicist at the City University of Hong Kong, says, “There’s a huge hope that we could eventually raise the critical temperature and make [such materials] more useful for applications.”
Optimism that Results Will be Replicated Soon
In the study’s conclusion, the researchers note they are exploring methods to get their nickelate to superconduct at normal pressure so that samples can “be better probed.” Li says this breakthrough would “allow physicists to use methods that would be challenging under high pressure, to better understand behavior of their electrons.”
The team also notes that their work is well documented and supported, unlike previous controversial claims of superconducting materials. Li agrees, noting that the quality of the evidence presented by the team is “absolutely great.” The researcher also suspects that other teams successfully reproducing the results are likely imminent.
“In China, I see people working day and night to synthesize new materials, to try to discover new physics about such systems,” Li explained.
Chen agrees, noting that “such fervent activity underscores the community’s optim—ism: nickelates may hold the key to unifying disparate theories of high-temperature superconductivity.”
The study “Ambient-pressure superconductivity onset above 40 K in (La, Pr)3Ni2O7 films” was published in Nature.
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.