Near-field microwave microscopy of one-dimensional nanostructures

With the ability to measure sample conductivity with nanometer spatial resolution, scanning microwave microscopy (SMM) is a powerful tool to study nanoscale electronic systems and devices. Here we demonstrate the general capability to image electronic variations within nanomaterials using nanowires of VO
₂
and Si as model systems. For VO
₂
we image the temperature-dependent metal-insulator domain coexistence that arises due to the built-in strain in substrate-clamped wires. In Si NWs integrated into a transistor device architecture we observe large increases in the source-drain current with the tip passing over the wire, correlated with variations in the SMM signal. We attribute this effect to local rectification of the microwave signal by the local tip-sample Schottky junction.