It serves as an analytical tool with simultaneous femtosecond temporal and nanometer spatial resolution. Moreover, UTEM also provides for a unique test bench to study quantum optics phenomena with free electrons.
This talk will introduce the implementation of UTEM with nanoscale field emitter sources, which offer ultrashort electron pulses of exceptional beam quality and spatial coherence. Examples of structural and magnetization dynamics probed by UTEM will be discussed. Moreover, the mechanisms involved in free-electron beams interacting with optical fields near nanostructures and surfaces will be described, emphasizing quantum effects. The coherent manipulation of the longitudinal and transverse degrees of freedom of free-electron wave functions is shown, and the preparation and characterization of attosecond electron pulse trains will be demonstrated.
 A. Feist et al., “Ultrafast transmission electron microscopy using a laser-driven field emitter: Femtosecond resolution with a high coherence electron beam”, Ultramicroscopy 176, 63 (2017).
 A. Feist et al., “Nanoscale diffractive probing of strain dynamics in ultrafast transmission electron microscopy”, Struct. Dyn. 5, 014302 (2018).
 A. Feist, K. E. Echternkamp, J. Schauss, S. V. Yalunin, S. Schäfer, and C. Ropers, “Quantum coherent optical phase modulation in an ultrafast transmission electron microscope”, Nature 521, 200 (2015).
 K. E. Echternkamp, A. Feist, S. Schäfer, and C. Ropers, “Ramsey-type phase control of free electron beams”, Nature Phys. 12, 1000 (2016).
 K. E. Priebe, C. Rathje, S. V. Yalunin, T. Hohage, A. Feist, S. Schäfer, and C. Ropers, “Attosecond Electron Pulse Trains and Quantum State Reconstruction in Ultrafast Transmission Electron Microscopy”, Nat. Phot. 11, 793 (2017)