HYBRID: Microscopy at the Extremes: Capturing Ultrafast Dynamics at the Atomic Scale

This lecture will be held in presence in the Anna-von-Helmholtz-Bau of the Physikalisch-Technische Bundesanstalt in Berlin-Charlottenburg and can be followed online at the same time. Please use the links above to register your personal participation or to receive the access data for online participation.

Topic:

Modern electronic and quantum devices are approaching atomic dimensions and operate at ever faster clock rates - reaching the intrinsic spatiotemporal scales of their condensed matter components, ranging from angstroms (1 Å=10^(-10) m) to femtoseconds (1 fs=10^(-15)  s). At the same time, resolving dynamical physical phenomena at these extremes has become essential for addressing key questions in condensed matter physics - such as how electrons and phonons move or localize in complex quantum materials, how energy redistributes in time and space, or how phase transitions evolve in the presence of disorder and near defects. Addressing these challenges requires the development of new microscopy techniques capable of probing quantum matter with simultaneous angstrom and femtosecond resolution. To achieve this, we combine two powerful experimental approaches: scanning tunneling microscopy (STM), which can resolve individual atoms and electronic quantum states at surfaces, and ultrafast pump-probe spectroscopy, which can capture femtosecond dynamics in condensed matter. In this talk, I will introduce the working principles of ultrafast STM and present recent results from our group, illustrating how this technique can be used to study non-equilibrium dynamics locally at the atomic scale.

CV:

Melanie Müller studied physics in Mainz, Germany, where she received her diploma in quantum optics in 2010. She then moved to the Fritz Haber Institute (FHI) in Berlin Dahlem in 2011 to join the research group of Ralph Ernstorfer, where she completed her Ph.D. in 2016 on ultrafast low-energy electron imaging and microscopy. After a short postdoctoral period in 2017, she started her own research group at FHI focusing on ultrafast scanning probe microscopy with the aim of exploring the smallest spatiotemporal scales in ultrafast surface science. Since January 2025, her research has been funded by an independent ERC Starting Grant, aiming to explore and control dynamical phenomena in quantum materials at the atomic scale.

Following the lecture, there will be a get-together where participants can exchange ideas with each other over pizza and drinks.

The event is sponsored by the Wilhelm and Else Heraeus Foundation.