Gate bias controlled NDR in an in-plane-gate quantum dot transistor

We report transport measurements through an in-plane-gate quantum dot transistor (IPGQDT). Our IPGQDT has etched trench isolation between the two-dimensional electron gas QD and IPGs, and it operates in enhancement mode. At relatively small IPG biases, we observe negative differential resistance (NDR) in the current–voltage characteristics. The position of the NDR peak is controlled systematically by the change of the IPG bias. At large biases, the IPGQDT exhibits single-electron tunneling. All of these transport data are not sample specific and consistent with the size of the QD.