9802756 Anlage This award provides partial support for the acquisition and development of a cryogenic scanned near-field microwave microscope which will measure important materials properties (such as surface sheet resistance, complex dielectric permittivity, complex magnetic permeability, etc.) at microwave frequencies with a spatial resolution on the order of 10 nm. The cryogenic operation will allow us to develop a superconducting near-field microwave microscope with greatly enhanced sensitivity. The microscope will also be configured to measure microwave current distributions in superconducting microwave devices at 100 nm resolution, for the purpose of understanding the microscopic origins of nonlinearity in these devices. In one mode of operation, we will obtain high spatial resolution microwave images which will be free of the effects of sample topography. In other configurations, the microscope will also use a scanning bolometer to measure spatially resolved temperature variations in superconducting microwave devices. A scanning single-electron transistor, operating at 4.2 K, will be used to sensitively image very small electric fields and charges. Finally, the microscope will be used in conjunction with an existing microwave network analyzer for imaging with calibrated broadband electromagnetic field and conductivity measurements. %%% ***
