Solid State Physics Laboratory, ETH Zurich, 8093 Zurich, Switzerland.
Nat Commun. 2011;2:239. doi: 10.1038/ncomms1241.
The coupling between a two-level system and its environment leads to decoherence. Within the context of coherent manipulation of electronic or quasiparticle states in nanostructures, it is crucial to understand the sources of decoherence. Here we study the effect of electron-phonon coupling in a graphene and an InAs nanowire double quantum dot (DQD). Our measurements reveal oscillations of the DQD current periodic in energy detuning between the two levels. These periodic peaks are more pronounced in the nanowire than in graphene, and disappear when the temperature is increased. We attribute the oscillations to an interference effect between two alternative inelastic decay paths involving acoustic phonons present in these materials. This interpretation predicts the oscillations to wash out when temperature is increased, as observed experimentally.
两能级系统与其环境的耦合会导致退相干。在对纳米结构中的电子或准粒子态进行相干操控的背景下，理解退相干的来源至关重要。在这里，我们研究了在石墨烯和 InAs 纳米线双量子点（DQD）中电子-声子耦合的影响。我们的测量揭示了 DQD 电流在两个能级之间的能量失谐上呈现周期性的振荡。这些周期性峰值在纳米线中比在石墨烯中更为明显，并且随着温度的升高而消失。我们将这些振荡归因于涉及这些材料中存在的声子的两种替代非弹性衰减路径之间的干涉效应。这种解释预测随着实验中观察到的温度升高，振荡会逐渐消失。
