Anomalous suppression of single-electron tunnelling observed for Si nanobridge transistors with a suspended quantum dot cavity

Recent advance on fabricating silicon nano electromechanical systems (NEMS) has enabled us to study single-electron tunnelling through nanometerscale suspended structures with restrained coupling to the environment. In particular, a suspended quantum dot cavity structure built on a Si nanobridge provides an ideal system to explore the interaction of single electrons with tailored phonon spectrum in the cavity which is acoustically isolated from the Si substrate. Such a system has recently become of great interest in terms of studying physics of decoherence mechanisms for quantum bits and also revealing ultimate energy dissipation process in Si nanostructures.Here, we report on anomalous suppression of single-electron tunnelling observed for a low source-to-drain region. These characteristics are attributable to the enhanced interaction between tunneling electrons and cavity phonons.