Science  Alert April 27, 2022
An international team of researchers (Germany, China, the Netherlands, USA – Johns Hopkins University) fabricated an inversion symmetry breaking van der Waals heterostructure of NbSe2/Nb3Br8/NbSe2. They demonstrated that even without a magnetic field, the junction can be superconducting with a positive current while being resistive with a negative current. The ΔIc behaviour (the difference between positive and negative critical currents) with magnetic field is symmetric and Josephson coupling was proved through the Fraunhofer pattern. They achieved stable half-wave rectification of a square-wave excitation with a very low switching current density, high rectification ratio and high robustness. This non-reciprocal behaviour strongly violates the known Josephson relations and opens the door to discover new mechanisms and physical phenomena through integration of quantum materials with Josephson junctions and provides new avenues for superconducting quantum devices… read more. TECHNICAL ARTICLEÂ
Schematic and superconductivity of the JD at zero field. Credit: Nature volume 604, pages653–656 (2022)Â