The observation of Josephson diode effect (JDE) is reported in hybrid devices made from semiconductor InAs nanosheets and superconductor Al contacts. By applying an in-plane magnetic field (Bxy), non-reciprocal superconducting switching current as well as non-reciprocal superconducting retrapping current are detected. The strength of the JDE depends on the angle between the in-plane magnetic field and the bias current (Ib), reaching its maximum when Bxy⊥I_b and dropping to nearly zero when Bxy//Ib. Additionally, the diode efficiency is tunable via an electrostatic gate with a complete suppression at certain gate voltages. These findings indicate that the observed JDE in InAs nanosheet-based Josephson junctions most likely arises from the Rashba spin-orbit interaction (SOI) in the nanosheets. Such gate-tunable JDE in Josephson junctions made from semiconductor materials with SOI is useful not only for constructing advanced superconducting electronics but also for detecting novel superconducting states.

Paper link: https://advanced.onlinelibrary.wiley.com/doi/10.1002/adfm.202503401