Van der Waals colloquium by dr. Antonija Grubišić Čabo from the University of Groningen (Netherlands) on "Deciphering the electronic structure of 2D materials in and out of equilibrium". Antonija's lab developed ultra-clean exfoliation of monolayer van der Waals materials and investigates these through photoemission spectroscopy.

Abstract:
The physics of solids, including atomically thin two-dimensional (2D) materials, is determined by their electronic band structure. Therefore, the investigation of electronic band structures is of great importance for the understanding, tailoring and discovery of new states of matter. Due to their atomic thickness, 2D materials such as graphene and single-layer transition metal dichalcogenides (TMDCs) are highly sensitive to the surrounding environment, and even small changes to their surroundings can alter their properties drastically. As such, there is a need for techniques that enable the determination of the electronic structure of materials with minimal impact on the probed sample. One such technique is angle-resolved photoemission spectroscopy (ARPES), which provides direct images of the electronic bands in the material. Time-resolved ARPES is a particularly useful extension of ARPES, which provides additional information about changes to the electronic structure that occur when a material is brought out of equilibrium. In this colloquium, I will show how we can experimentally probe the electronic structures of 2D materials, what information time-resolved ARPES can provide, and how 2D TMDCs change in response to changes in the surroundings the material is placed in. Finally, I will show how we can control 2D materials with light, and briefly discuss a novel approach for 2D exfoliation.

The Joan van der Waals colloquium is an ongoing bi-weekly lecture series, organized by LION. As all speakers are instructed to give an accessible lecture for everyone, these lectures aid in getting a broader view of physics. Each colloquium is preceded by an opening act: a PhD student or postdoc from LION and a different field than the invited speaker, to give a 10-min presentation. After the colloquium, there is a chance to meet your colleagues and participate in discussions at the borrel. More information can be found here.