In July 2023, a team of researchers in South Korea posted a preprint claiming to have discovered a material that exhibited superconductivity at room temperature and ambient pressure. The material, a lead-copper-phosphate compound called LK-99, went instantly viral. Within days, labs around the world had attempted to replicate the result. Social media was flooded with videos of levitating samples. The stock prices of companies involved in superconductor research spiked. And then, within weeks, the replication attempts failed one by one. LK-99 was not a room-temperature superconductor. But the episode revealed something important about the state of the field — and about how scientific hype functions in the modern information environment.
Why Superconductivity Matters
Superconductors carry electricity with zero resistance. That means no energy is lost to heat during transmission, and currents can flow indefinitely without a power source. Power grids could transmit electricity without the estimated 5-8% of energy currently lost to resistance. MRI machines, which currently rely on liquid helium-cooled superconducting magnets, could operate without expensive, scarce cryogens. Magnetic levitation trains, magnetic energy storage, and vastly more powerful computing could all become practical. The economic value is difficult to overstate — a study by the National Academies estimated that a room-temperature, ambient-pressure superconductor could generate trillions of dollars in economic value over several decades.
The problem is that every known superconductor requires extreme conditions. Conventional superconductors — discovered in 1911 by Heike Kamerlingh Onnes — must be cooled to temperatures near absolute zero (-273°C). High-temperature superconductors, discovered in 1986, work at higher temperatures, up to about -140°C, but still require liquid nitrogen cooling. The holy grail is a material that superconducts at room temperature and ambient pressure, or at least at temperatures achievable with cheap refrigeration and pressures far below the million-atmosphere range required by some hydride superconductors.
What Actually Happened with LK-99
The LK-99 claim was met with immediate and intense scrutiny — a testament to how quickly the global scientific community can mobilise in the age of open preprints and social media. Researchers at the University of Maryland, the Chinese Academy of Sciences and numerous other institutions attempted replication. The verdict, published within weeks, was unambiguous: LK-99 does not superconduct. The partial levitation observed by the Korean team was caused by diamagnetism — a phenomenon exhibited by many materials, including ordinary water and bismuth — not by the Meissner effect, which is the defining characteristic of a true superconductor. The resistance drops observed in some samples were likely caused by copper sulfide impurities undergoing a phase transition. The LK-99 episode was a false alarm, a case of experimental enthusiasm overwhelming scientific rigour.
The Real Progress
But the LK-99 hype obscured genuine progress in the field. In 2023, the same year as the LK-99 debacle, researchers achieved a significant milestone: a superconductor operating at 20°C — room temperature — under a pressure of about 10,000 atmospheres. The material was a nitrogen-doped lutetium hydride, and while the required pressure is far too high for practical applications, the result represented a real advance in understanding how to tune hydride superconductors. In 2024, a separate team demonstrated a nickelate superconductor — a class of materials discovered in 2019 — operating at -73°C under ambient pressure, which, while still far from room temperature, is a meaningful improvement over previous high-temperature superconductors that required liquid helium cooling. The trajectory of the field suggests that genuine room-temperature superconductivity may be achievable, but likely decades away, and the path will be paved with rigorous replication rather than viral preprints. The lesson of LK-99 is not that the search is hopeless — it is that extraordinary claims require extraordinary evidence, and the scientific method, however imperfect, remains the best tool we have for separating genuine breakthrough from wishful thinking.
