Figure 1

a) Electron microscope image of the device used in the LPR and schematic of the experimental setup. RF and DC voltage are applied to the finger-gate (red) and only DC voltage is applied to the split-gate (green). b) Numerical derivative pump maps in the CPR (\(f=180\) MHz with amplitude \(\text{Amp}=1\) V\(_{\text{pp}}\)) and LPR (fundamental \(f = 181.81\) MHz with \(\text{Amp}=1\) V\(_{\text{pp}}\)) of the pumped current with a tailored trapezoidal signal from the AWG applied in the LPR. c) Schematic showing the same snap shot during the pump cycle for different \(V_{\text{SD}}\) bias \(V_{\text{SD}}\) regimes. The dotted lines in the left and right schematic correspond to the form of the exit barrier in the middle schematic where \(V_{\text{SD}}=0\) and is used as a comparative reference point