An international team of researchers from Japan’s Materials Research Institute, Tohoku University, the University of Tokyo and the Institute of Science and Chemistry found through computer simulations that at superconducting high pressure near room temperature (-23 degrees C), the hydroxide radon (LaH10) is a stable “quantum solid” in a wide range of pressure regions through quantum fluctuations in the nucleus.
The findings suggest that high-temperature superconductivity and room temperature superconductivity can be achieved at much lower pressure than expected by hydrogen-rich compounds containing large amounts of hydrogen.
Superconductive materials with zero resistance, transmission without energy loss, is expected to solve the environmental energy problems and attention. Realizing room temperature superconductivity is the dream of mankind, and many studies have been done for a long time. In 2019, it was reported that at 130-220GPa high pressure, LaH10 with a cubic crystal structure was near lying at room temperature at an absolute temperature of 250K (-23 degrees C), setting a new record for superconducting transfer temperature and stable in this wide pressure range. But so far, the theoretical calculation predicts that stabilizing this structure requires at least 230GPa or higher pressure, and why the stability of the cubic crystal structure will be more concerned than the theoretical prediction of 100GPa pressure.
The team notes that the theoretical calculations so far ignore quantum fluctuations in the nucleus. Using computer simulations that add edgy quantum fluctuations in atomic nuclei, they found that the hydrogenated niobium-hydrogenated niobium quantum fluctuations were extremely high, and the cubic crystal structure LaH10 showed a stable “quantum solid” state in a wide range of pressure fields due to quantum fluctuation seamounts. In addition, with the new calculations, they also accurately described the superconducting transfer temperature obtained in the experiment, including pressure dependence.
Since quantum fluctuations in the nucleus are common in most substances, the team hopes to find other hydrogen-rich compounds to replace hydrogenated niobium. The theoretical accuracy of predicting the composition and structure of similar substitute substances is improved by using the simulation method of adding quantum fluctuations. The theoretical prediction of room temperature superconducting materials can help to find a more suitable target material.
The results were published in the recent nature website.