Current-reversal operation for a single-parameter electron pump by control of semiconductor-based cryo-switch gate potentials

The reversal technique in electrical measurements has been generally used to obtain a genuine value of an interesting physical quantity without unwanted signal offset. In the present work, we developed a novel cryo-switch made of electrical gates on GaAs heterostructure and demonstrate the current-reversal operation for a single-parameter electron pump. In precision measurements, we confirmed that the current values in reversal (i.e., approximately ±12.817 pA) being generated by the electron pump at T = 4.2 K agree well with each other in the deviation and uncertainty levels for various exit gate voltages. We also show that the accuracy level evaluated via the difference between the currents reversed was consistent with the unipolar measurements. Consequently, the measurement uncertainty was improved by a factor of two with the same measurement cycle number because of enhancement of signal-to-noise ratio.