Coulomb blockade oscillations as a noninvasive probe of screening

Noninvasive measurement techniques utilize the fact that the local conditions in an electrical circuit can affect a nearby, but electrically isolated circuit. Such a technique can be used to measure the screening ability of an electron system. In this work, we study non-invasively the screening characteristics of a one-dimensional (1D) channel in close lateral proximity to a quantum dot that forms a separate and electrically isolated circuit. We use a one-dimensional (1D) channel to screen and in-plane electric field between the gate and the lateral quantum dot. The Coulomb blockade oscillations we observe through the quantum dot circuit and the corresponding variation in their periodicity at different gate voltage regions are a signature of the screening characteristics of a 1D channel both at zero magnetic field and in the quantum Hall region. The screening ability of the 1D channel is found to be approximately two orders of magnitude smaller than that of an ungated GaAs two-dimensional electron system.