Experimental Progress towards Probing the Ground State of an Electron-Hole Bilayer by Low-Temperature Transport

Figure 8

Diagram showing that a sign reversal of any error in drag due to excitation current leaking between layers is expected when biasing points (named C1, C2, D1, and D2) are altered, as direction in drag layer changed. A little bit of the drive current may be leaking into the other layer and flowing through a parallel path that includes part of the second layer. The resistive drop due to this would appear between the voltage probes. But it is possible to decide whether the measured voltage is due to this. If we change the point at which the second layer is grounded, the path of the leakage current would then be reversed causing the measured voltage to change. Thus, by shifting the point at which the “drag layer” is voltage referenced, we can verify if the measured voltage was due to leakage or not.