Oscillatory conductance in a double-bend quantum dot device

We have successfully observed negative differential conductance in an electrostatically confined double-bend quantum dot device at low temperatures under different source-drain bias conditions. The structure fabricated on a modulation-doped GaAs/AlGaAs layer consists of a zero-dimensional (0D) submicrometre dot that is connected to wide source and drain regions via one-dimensional (1D) leads. By changing the external gate voltage, the size of the dot and 1D leads can be altered. Conductance oscillations have been observed for temperatures as high as 7 K. To our knowledge such oscillations have not previously been reported in similar laterally confined quantum dot devices at such high temperatures.