Measurement and analysis of the height of potential barrier and depth of moving potential dot in the quantum point contact

•The quantized acoustoelectric (AE) current plateaus in the I (Vg) characteristics were measured.•The height of electrostatic potential of gate voltage in the quantized AE plateau of SAWSET devices was estimated.•For the SAWSET device designed by wet etching technique, the conversion efficiency of the gate voltage is about 0.67 meV/mV.•The largest probability of electron tunneling to the source is ωt/π = 0.78 and 1.22.•The lowest depths of moving quantum dots in the first and second quantized AE current plateau were obtained. Employing the measure of I (Vds) characteristics (current versus bias voltage) at fixed gate voltages, the height of potential barrier in the quantized acoustoelectric (AE) current plateau region was estimated and analyzed. The results show that the height of the electrostatic potential of gate voltage in the first quantized AE plateau was in the range from 216 to 222 meV, while that was about 200 meV in the second quantized AE plateau. And the conversion efficiency of the gate voltage is approximately 0.67 meV/mV, which is higher than the data (0.3 meV/mV) of the device designed by split gate technique. The positions of minimum depth of moving potential dots are ωt=0.78π and 1.22π in a SAW cycle, and the lowest depth in the first quantized AE current plateau is about 6.5 meV, while the lowest depth is 12.6 meV in the second quantized AE current plateau.