FLUCTUATIONS IN THE TRANSMISSION PROPERTIES OF A QUANTUM-DOT WITH INTERFACE ROUGHNESS AND IMPURITIES

We examine statistical fluctuations in the transmission properties of quantum dots with interface roughness and neutral impurities. For this purpose we employ a supercell model of quantum transport capable of s imulating potential variations in three dimensions. We find that sampl e to sample variations in interface roughness in a quantum dot wavegui de can lead to substantial fluctuations in the n = 1 transmission reso nance position, width and maximum. We also find that a strongly attrac tive impurity near the centre of a quantum dot can reduce these fluctu ations. Nevertheless, the presence of more than a single impurity can give rise to a complex resonance structure that varies with impurity c onfiguration.