For the first time in the world, a research group at the University of Tokyo has discovered that a two-dimensional superconductor with broken spatial inversion symmetry exhibits rectification characteristics (diode characteristics) when a magnetic field is applied in a specific direction.
In the superconducting state, the electric resistance becomes zero and electricity can flow without generating power consumption, so the development of superconducting nanoelectronics has been required especially in the fields such as next-generation computing systems.Above all, the development of superconductors with rectifying properties, that is, superconducting diodes, was extremely important.
Using a single crystal of molybdenum disulfide, the research group created a model that can artificially realize two-dimensional superconductivity with broken spatial inversion symmetry.Until now, it has been clear that normal conductor crystals with broken spatial inversion symmetry have rectifying properties, but this has not been studied for superconductors.The electrical conduction characteristics were measured with a magnetic field applied in the direction perpendicular to the plane of this device.
According to the research results, extremely large rectification characteristics were observed in the superconducting state compared to the normal conducting state.Furthermore, we have seen an increase in this rectifying characteristic near the temperature at which it shifts to superconductivity, and succeeded in elucidating the theory.This phenomenon is explained to be universal to general superconductors with broken spatial inversion symmetry.
It can be said that this result will not only be the foundation for opening up a new academic field of two-dimensional superconductivity with broken symmetry, but will also provide important knowledge for the functional development of superconducting nanoelectronic materials.
Paper information: [Science Advances] Nonreciprocal charge transport in noncentrosymmetric superconductors