Fig. 4: Modelling supercurrent across a nanobridge for sign-tunable diode effect.
From: Sign reversal diode effect in superconducting Dayem nanobridges
a Sketch of the theoretical framework for model I, with the arrows indicating the phase winding associated with a vortex nucleated near the grain boundary. Characteristic CPR (red line) of the weak link hosting a vortex close to the grain boundary. b Nonreciprocal rectification efficiency η calculated for a few values of the second harmonic at a given position of the vortex core with (xv, yv) = (0.4 w, 0.4 w) and γv = 1. c Nonreciprocal rectification efficiency η for different positions (xv) of the vortex with yv = 0.4w and I2,0 = 0.2. Variation of the vortex position leads to substantial modifications in η at low magnetic fields. d Sketch of the nanobridge, with SS’S indicating the regions with different amplitudes of the superconducting gap. Here we assume the presence of Rashba and Dresselhaus spin-orbit couplings. Representative skewed and asymmetric CPR (red line) originated by high-harmonic components (up to the third one) and an anomalous phase offset φ0. e Nonreciprocal rectification efficiency η calculated for several values of the third harmonic component I3,0, assuming that I1,0 = 1, I2,0 = − 0.3 and ΓB = 0.2B/B*. η changes sign after maximum rectification is reached. f Impact of the fourth harmonic in the rectification, with I1,0 = 1, I2,0 = − 0.3 and I3,0 = 0.25.
