A joint research team consisting of the Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Japan National Research and Development Corporation Materials Research Institute and the National High Magnetic Field Laboratory recently demonstrated that the most promising iron-based superconductor The electronic state of the parent material, CaFeAsF, confirmed the presence of Dirac electrons.
Iron-based superconductors, which were discovered in 2008, have drawn much attention as potential candidates for high-temperature superconductors due to their high transition temperatures, and in superconductivity research, there is a need to find new superconductors by replacing some elements of the parent material. It is very important to explain the cause of high temperature superconductivity to clarify the electronic state of the parent material, but it is very difficult to make the precursor of iron-based superconductors with high superconducting transition temperature. It is difficult to obtain high quality samples with few impurities and defects. The experimental analysis has been unable to make progress.
The team completely identified the Fermi surface of CaFeAsF, the parent material for iron-based superconductors, which shows the most energetic electronic state. Using high-quality CaFeAsF single crystals synthesized by a Chinese research team, the Japanese and U.S. teams measured quantum oscillations in a cryogenic magnetic field , Successfully completed the Fermi surface experimental observations, the measured values of the Fermi surface consistent with the theoretical prediction.From the detailed analysis of the quantum oscillation, the team found that Fermi surface is a special type of electronic known as Dirac electron Formation of such electrons in the solid moving at high speed and less susceptible to impurities.
The latest research explains the electronic state of the parent material CaFeAsF as an important basic understanding of the origins of iron-based superconductors, and confirming the existence of Dirac electrons will help develop electronic devices that combine the new capabilities of superconductivity and Dirac electronics .
