Exploring the microscopic structure of ultracold quantum gases
Prof. Dr. Herwig Ott (Fachbereich Physik, Universität Kaiserslautern)

Scanning electron microscopy is routinely used to study solid objects on a nanometer scale. Applied to ultracold quantum gases it constitutes a powerful imaging and manipulation technique that combines single atom sensitivity with high spatial resolution.
We have adapted a scanning electron microscope for the study of ultracold quantum gases. The focussed electron beam ionizes the atoms which are subsequently detected. The technique allows for high precision density measurements of the trapped gas with a spatial resolution of better than 150 nm. We demonstrate single site addressability in an optical lattice and show that one can produce arbitrary patterns of occupied lattice sites. The electron beam can also be used to locally introduce losses, thus paving the way to investigate dissipative processes in quantum gases. The technique also allowed us to study spatial and temporal pair correlation functions, ranging from bunching signals in thermal clouds to antibunching signals in strongly correlated one-dimensional Bose gases.