The optics of quantum materials group is looking for an enthusiastic PhD candidate to join a cutting-edge experimental physics project at the interface of ultrafast science and quantum materials. This is an opportunity to do science that has simply never been possible before.

Modern electron microscopes can map materials with sub-Ångstrom spatial resolution and, in combination with an energy analyser, detect fundamental excitations of quantum materials using Electron Energy Loss Spectroscopy (EELS). Most measurements yield a static or time-averaged picture, while the non-equilibrium dynamics that govern heat transport, charge flow, and phase transitions unfold on femtosecond (10⁻¹⁵ s) timescales.

Ultrafast TEM addresses this gap by combining femtosecond laser pulses with pulsed electron probes in a pump–probe scheme: a laser pulse triggers a physical process, and a precisely timed electron pulse images or spectroscopically probes the material a controlled time delay later. This NWO funded project, carried out in collaboration with Thermo Fisher Scientific and Doctor X works B.V., will push this technique to its limits through novel microwave cavity technology — achieving few-femtosecond temporal resolution in imaging mode, and few-tens-of-meV energy resolution in ultrafast EELS mode.

As a PhD candidate focusing on the scientific program, you will exploit these new capabilities to tackle two outstanding problems in condensed matter physics:

Memristive switching dynamics: HfO₂-based memristive devices are among the most promising candidates for neuromorphic computing, yet the microscopic mechanism of resistive switching — believed to involve the nucleation and growth of conducting filaments — remains poorly understood and difficult to control. You will use spatially resolved, time-resolved electron microscopy to directly image filament formation in real time with nanometre precision, providing the first direct experimental window into this process.

Strange metal dynamics: The "strange metal" phase of the high-temperature superconductor Bi₂Sr₂CuO₆ exhibits anomalous properties that challenge conventional theoretical models. Using ultrafast EELS, you will probe the dynamics of these fluctuations and compare the outcomes with measurements of the (static) optical conductivity.