Local Gating of Nanostructures with a Low-Temperature Scanned Probe Microscope

We have recently constructed a low-temperature scanned probe microscope designed to operate down to dilution refrigerator temperatures. There has been increasing interest in gaining spatial information about transport through nanostructures by using scanned probe microscopy$^{1-3}$. Our microscope incorporates a commercial stick-slip positioner for coarse approach and alignment to nanostructures. Here we present our solutions to some of the challenges faced in designing such an instrument, as well as a first set of low-temperature scanned probe images obtained from several nanostructures fabricated on different high-mobility GaAs/AlGaAs 2DEG heterostructures. \newline\newline $^{1}$ M.A. Topinka et al., Science \textbf{289}, 2323 (2000). \newline $^{2}$ R. Crook et al., Phys. Rev. Lett.,\textbf{ 91}, 246803 (2003). \newline $^{3}$ A. Pioda et al., Phys. Rev. Lett., \textbf{93}, 216801 (2004).