EFFECTS OF POTENTIAL FLUCTUATIONS IN QUANTUM-DOT ON COULOMB OSCILLATION

We report how the conductance oscillations are varied when there are p otential fluctuations in the semiconductor quantum dot. We find that t he potential fluctuations lead to an irregular and a nonmonotonic chan ge of the peak heights as a function of the gate voltage and each one increases or decreases as a function of temperature from peak to peak. The details are sensitive to the change of the randomness in the pote ntial. We show that these anomalous features, although they differ fro m device to device, are observed universally when the fabrication is n ot complete.