Two level mixing effects probed by resonant tunnelling through vertically coupled quantum dots

Abstract

AbstractWe study the magnetic (B ‐) field evolution of single‐particle levels in one dot by observing resonant tunnelling (RT) between two weakly coupled vertical quantum dots in series. The B ‐field dependence of the RT current peaks in the spectrum follows closely that of the states of a circular two dimensional harmonic potential. Several prominent two‐level anti‐crossing features are revealed. The RT current changes dramatically on passing through the anti‐crossing point. This can be assigned to the nature of inter‐dot RT though intra‐dot level‐mixed states. (a) Schematic diagram of our device. (b) Measured anti‐cross in the resonant current induced by intra‐dot two level mixing. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)