Figure 1
From: High-accuracy current generation in the nanoampere regime from a silicon single-trap electron pump
(a) Schematic of the device structure with electrical connections. The trap should be located under the right edge of G1. R is an 1-GΩ standard resistor calibrated against the quantum Hall resistance standard. Voltage applied to R is measured using a voltmeter calibrated against the Josephson voltage standard. VR is the readout of the voltmeter. IR = VR/R is a reference current, and IDIF = IR − IP is the current difference between IR and the pumping current IP. (b) Electron potential diagram during the SE pumping via a single-trap level. S and D are the source and drain leads, respectively. (c) First derivative of IP with respect to VEXIT as a function of VEXIT and VENT at 6.5 GHz, where VUG = 1.3 V, VS = 0 V, and P = 14 dBm. (d) First derivative of IP with respect to VUG as a function of VUG and VENT at 6.5 GHz, where VEXIT = −0.8 V, VS = 0 V, and the power of the high-frequency signal P = 14 dBm. (e,f) Potential diagrams during the detrapping process. Increasing VENT lowers the potential of the entrance barrier (red arrows) and increasing both VEXIT and VUG lowers the island potential (blue arrows). Therefore, these voltage applications keep the electric field at the trap level constant. Note that the modulation of the exit barrier by VEXIT is not related to the detrapping process. (g) Potential diagram during the ejection process. Decreasing VENT raises (red arrow) the island potential; increasing VUG lowers (blue arrow) it. This keeps the island potential constant, leading to a constant ejection probability. Note that the modulation of the entrance barrier by VENT is not related to the ejection process.
