The project proposal consisted of four work packages: design, assembly, commissioning and first scientific study using the new equipment. The design of the microscope head and its construction were swift and successful, allowing for atomic resolution imaging in air of graphite. The design and construction of the probe with which to cool the microscope down to 4K and eventually 0.3K took longer than anticipated – due to a design flaw that had to be corrected and an underestimation of the time it took to receive all components. However, once completed, the microscope has successfully been cooled down to 4K and calibration of both the conventional operation of the microscope at low temperature and the novel circuitry for shot noise measurements followed. Eventually, after fine tuning various components and optimising the circuitry, shot noise could reliably be measured at the atomic scale on a gold surface. The specific method for measuring shot noise using the microscope, and the first atomic scale shot noise measurements performed, will be published in the near future. The final phase of the action was to apply the novel technique to the a correlated electron system. Originally a Kondo system consisting of a cobalt atom on a gold surface were proposed. However, it was decided instead to measure the high temperature superconductor Bi2Sr2CaCuO8+x (e.g. Bi2212) on which high quality conventional STM measurements have been performed with the microscope that was constructed during this action, including atomic resolution topography, spectroscopy and quasi particle interference scattering measurements. The attached image (SN-STM-01.jpg) show the design of the microscope and low temperature probe (left), the actual instrument, and atomic resolution topography (right top) and spectroscopy (right bottom) of Bi2212. Additionally, simultaneous atomic scale shot noise measurements have been performed with a resolution on the slope of the noise – which is directly related to the charge and the Fano factor – of a few percent.
