A superconductor is a material that exhibits superconductivity. It loses all electrical resistance and expels magnetic flux fields when cooled down to a certain temperature or when it reaches its critical temperature. This allows an electric current to flow indefinitely without loss of energy. A room-temperature superconductor is a material that exhibits superconductivity at operating temperatures that can be maintained in an everyday environment.
What is a Room-Temperature Superconductor? How Does It Work? What are the Challenges in Producing a Room-Temperature Superconductor? What Are Its Potential Applications?
Description and Properties
Electrical conductors are materials that allow the flow of electric charge or electric current in one or more directions with low resistance due to their atomic structure. Metals are the most common and widely available examples of these conductors. However, because resistance is still possible, these common conducts still impede the flow of electric current which results in electrical energy converting into head, thus leading to energy loss.
Superconductors have no electrical resistance when cooled below their respective critical temperatures. The existence of this material was proven in 1911 when Dutch physicist Heike Kamerlingh discovered and described the superconductivity phenomenon. Furthermore, aside from zero resistance, superconductors exhibit the Meissner effect, which expels magnetic fields from their interior, thus making perfect diamagnets.
It would appear that superconductors are a suitable alternative to common conductors. However, it is important to reiterate the fact that these materials demonstrate superconductivity only when cooled below their critical temperatures. Most superconductors require extremely low temperatures to maintain their superconducting state. This limits the practical applications and widespread utilization of these materials.
Take note that high-temperature superconductors are materials that exhibit superconductivity at temperatures above the boiling point of liquid nitrogen or -196.2 degrees Celsius. These materials still need cooling and are also considered impractical for wider applications. However, since their discovery, several researchers have hypothesized the possible existence of materials that can maintain their superconducting state at room temperature.
Nevertheless, in consideration of the aforesaid characteristics and properties of superconductors, so-called room-temperature superconductors are hypothetical materials that exhibit zero electrical resistance and the Meissner effect at operating temperatures above zero degrees Celsius. These temperatures can be reached and maintained in a natural environment. Several researchers have ventured into discovering and producing these materials.
Challenges in Production
Researchers E. Snider et al. published a paper in 2020 in the journal Nature that described a potential candidate for a room-temperature superconductor. The material was an extremely pressurized carbonaceous sulfur hydride with a critical transition temperature of 15 degrees Celsius at 267 gigapascals. However, in the same year, the editorial board of Nature retracted the paper due to a non-standard and user-defined data analysis.
Furthermore, in 2023, South Korean researchers Sukbae Lee, Ji-Hoon Kim, and Young-Won Kwon published two papers on the preprint server arXiv.org that presented the material called LK-99, which was a modified lead-apatite, as the first room-temperature and ambient-pressure superconductor. The team claimed that the material exhibited superconductivity at a temperature of around 59 degrees Celsius and ambient pressure.
The papers drew excitement and criticism across the scientific community and the general public. The reaction of other scientists was mainly skeptical due to the extraordinary nature of the claim and notable errors and inconsistencies in the preprint papers. Strong skepticism is the default response to claims about room-temperature superconductors due to the history of poor reproduction and allegations of scientific misconduct.
Understanding the mechanism behind superconductors at high temperatures remains the biggest challenge in producing room-temperature superconductors. This translates further to identifying and synthesizing or engineering materials that can exhibit superconducting properties at or above room temperature. It is also important to note that some known superconductors are unstable and sensitive. This makes their integration into current technologies difficult.
Potential Applications
However, once discovered, a room-temperature superconductor, that can also operate under ambient pressure, has the potential to revolutionize societies and economies. It is important to underscore the fact that superconductors are applied in magnetic resonance imaging, nuclear magnetic resonance, particle accelerators, fusion energy research, and superconducting quantum interference devices. These applications are obviously limited.
The arrival and eventual mass production of room-temperature superconductors would be favorably disruptive. These materials can be used in power grids and improve their efficiencies. Take note that about 100 billion kWh of electricity is wasted on transmission losses each year in the United States alone. This amount of electricity is equivalent to the generation capacity of large nuclear reactors running round-the-clock for a year.
Room-temperature superconductors can advance current nuclear fusion research. Some nuclear fusion reactors depend on superconductors to control and confine the plasma. Proposed designs use materials that require special cooling to maintain their superconducting state. This creates a huge temperature gradient and operational challenges. Failure to maintain superconductivity can damage the reactor and lead to a meltdown.
The same materials can also herald new computing architectures and advanced consumer electronic devices. Take note that quantum computers use superconductors to stabilize quantum bits or qubits. These qubits are fragile and sensitive to interferences such as heat and electromagnetic fields. Superconductors help in creating and maintaining quantum states with minimal to zero heat-inducing and noise-producing energy loss.
Another potential application of room-temperature superconductors is in the development of faster and more efficient processors or chips. These chips would be faster, consume less energy, be smaller, and generate very minimal heat due to the overall electrical efficiency of the superconducting material. Specific applications include powerful personal computers, smartphones, and even smaller smart devices like wearables.
FURTHER READINGS AND REFERENCES
- Lee, S., Kim, J.-H., and Kwon, Y.-W. 2023. “The First Room-Temperature Ambient-Pressure Superconductor (Version 1).” arXiv. DOI: 48550/ARXIV.2307.12008
- Lee, S., Kim, J.-H., and Kwon, Y.-W. 2023. Superconductor Pb10−xCux(PO4)6O Showing Levitation at Room Temperature and Atmospheric Pressure and Mechanism. arXiv. DOI: 48550/arXiv.2307.12037
- Snider, E., Dasenbrock-Gammon, N., McBride, R., Debessai, M., Vindana, H., Vencatasamy, K., Lawler, K. V., Salamat, A., and Dias, R. P. 2020. “Publisher Correction: Room-Temperature Superconductivity in a Carbonaceous Sulfur Hydride.” Nature. 588(7837): E18. DOI: 1038/s41586-020-2955-8