Fig. 3: Interference at ν = 2.
a QPC conductance versus gate voltage at ν = 2. A robust conductance plateau at \(G=2\frac{{e}^{2}}{h}\) is observed, indicating full transmission of two edge modes of the N = 0 Landau level. However, a sharp plateau at \(G=\frac{{e}^{2}}{h}\) is not evident, likely due to the smallness of the spin gap at B = 1.25 T. Red circles indicate the QPC settings for partial transmission of the inner mode and outer mode of the N = 0 Landau level. b Interference while partially transmitting the inner edge mode (spin-up N = 0 Landau level). c 2D FFTs of interference for the inner mode and the outer mode in the compressible and incompressible regimes at ν = 2. d Interference while partially transmitting the outer edge (spin-down N = 0 Landau level). For interference of both the inner and outer modes, the data display a larger magnetic field period near the plateau center, indicating an incompressible bulk. At lower fields, a smaller period accompanied by numerous phase modulations is observed, suggesting a compressible bulk. Black dashed lines in panel d highlight the discrete phase slips within the incompressible region when interfering the outer edge mode at ν = 2. e Plot of the magnitude of discontinuous phase slips observed in Fig. 3d with \(\overline{\Delta \theta }/2\pi \approx 0.38\). f Differential conductance versus DC source-drain bias and plunger gate voltage. g FFT amplitude of the differential conductance vs. DC source-drain bias. The FFT amplitude minimum corresponds to the nodes in the interference, allowing extraction of ΔVSD1 ≈ 132 μV.
