South Korean researchers have claimed to have made a breakthrough in modern physics by discovering a new superconductor – the LK-99 – which operates at room temperature and ambient pressure. While the claim requires further research to verify, the discovery of a superconductor that operates without the need for extremely low temperatures has the potential to revolutionise a range of industries.
What is a Superconductor?
A superconductor is a material that can conduct electricity with perfect conductivity and zero resistance; however, this state is typically only achieved when the conductor is cooled below a critical temperature.
When a superconductor transitions into its superconducting state, electrons within it form “Cooper pairs”, where two electrons behave like a single particle, and flow freely without colliding with ions in the material’s lattice. This allows electrical current to flow with no energy loss due to resistance, which is not possible in normal conducting materials. The ability of electrons to pair up and flow without resistance only occurs at extremely low temperatures.
Once a superconductor reaches its critical temperature, it exhibits other unique properties like the Meissner effect, where magnetic fields are expelled from the material. These properties make superconductors promising for applications like efficient power transmission, magnetic levitation trains, and more sensitive detectors. However, their use is still limited by the need for extremely cold temperatures and high production costs.
The Significance of This Discovery for Clean Energy
The researchers claim to have created a new material based on a modified lead-apatite structure, called LK-99, which they say exhibits superconductivity even at room temperature. Lead apatite is an insulating calcium phosphate mineral in which some calcium ions have been replaced by lead ions. The researchers then replaced some of the lead ions in the insulating parts of the material with copper ions, causing the overall volume to shrink slightly by 0.48% – creating internal stress in the material. That stress then distorts the cylindrical layers of the material, forming thin layers that act like “quantum wells”. A quantum well is a thin layer that restricts electrons to two dimensions, enabling them to easily form Cooper pairs. When electrons pass through the quantum wells in this material, Cooper pair formation allows LK-99 to exhibit superconductivity even at room temperature.
The discovery of room-temperature superconductors – if verified and fully optimised – could represent a significant breakthrough towards a wide variety of applications, including low-cost MRI machines, compact and efficient motors, and quantum computing. However, its potential as a game-changer in the search for clean energy solutions is particularly noteworthy. This breakthrough eliminates the need for costly and energy-intensive cooling systems associated with traditional superconductors by enabling electricity transmission with zero resistance at ambient temperatures. As a result, highly efficient power transmission lines, energy storage devices, and electric motors can be developed, leading to a substantial reduction in energy waste and an overall increase in energy efficiency. Moreover, room-temperature superconductors could facilitate the widespread adoption of renewable energy sources by efficiently integrating them into existing power grids and overcoming the limitations of intermittent generation. The practical implementation of such a superconductor holds the potential to revolutionise the energy landscape.
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Not So Fast
Despite the excitement, researchers have called for caution in interpreting the findings.
Michael Norman, a theorist at Argonne National Laboratory, expresses scepticism regarding the solidity of the explanations provided in the papers. He highlights that substituting copper atoms for lead atoms in lead apatite, a nonconducting mineral, should not significantly impact its electrical properties. Norman also emphasises that the heavy weight of lead atoms is expected to impede the formation of the electron pairs necessary for superconductivity. Furthermore, the proposition of 1D channels for superconductivity and the introduction of disorder through doping raise additional doubts.
Given these uncertainties, the study requires rigorous peer review and independent replication of the experiments before firm conclusions can be drawn regarding the validity of the findings. John Durrell, Professor of Superconductor Engineering at Cambridge University, added that a practical room temperature superconductor would be potentially transformative, but even if the claims are true, it could take one or two decades to turn a newly discovered superconducting material into a practical material.
Further research is needed to verify the claims, including understanding the fundamental mechanisms behind the superconductivity, exploring potential limitations and challenges, and investigating the scalability and manufacturability for potential real-world applications. However, subject to the validity of the results, the discovery of LK-99 could represent one of the most significant achievements of the last few decades in physics and material engineering.
Featured image: Wikimedia Commons.