The features of ballistic electron transport in a suspended quantum point contact

A suspended quantum point contact and the effects of the suspension are investigated by performing identical electrical measurements on the same experimental sample before and after the suspension. In both cases, the sample demonstrates conductance quantization. However, the suspended quantum point contact shows certain features not observed before the suspension, namely, plateaus at the conductance values being non-integer multiples of the conductance quantum, including the 0.7-anomaly. These features can be attributed to the strengthening of electron-electron interaction because of the electric field confinement within the suspended membrane. Thus, the suspended quantum point contact represents a one-dimensional system with strong electron-electron interaction. (C) 2014 AIP Publishing LLC.