Second Quantization: Gating a Quantum Dot Through the Sequential Removal of Single Electrons from a Nanoscale Floating Gate

Abstract

We use the tip of an atomic force microscope (AFM) to charge floating metallic gates defined on the surface of a Si/SiGe heterostructure. The AFM tip serves as an ideal and movable cryogenic switch, allowing us to bias a floating gate to a specific voltage and then lock the charge on the gate by withdrawing the tip. Biasing with an AFM tip allows us to reduce the size of a quantum dot floating gate electrode down to $\sim 100\mathrm{nm}$. Measurements of the conductance through a quantum dot formed beneath the floating gate indicate that its charge changes in discrete steps. From the statistics of the single-electron leakage events, we determine the floating gate leakage resistance $R\sim 10^{19}\mathrm{Ohm}$ - a value immeasurable by conventional means.

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Cited by in corpus (1)

• Dispersive readout of a silicon quantum device using an atomic force microscope-based rf gate sensor