Promotionsvortrag Physik: „High-Resolution Spectroscopy of Single Molecules on a Crystal Surface“

Ankündigung des Promotionsvortrags von Herrn Masoud Mirzaei:

and technological applications. Single-molecule spectroscopy offers a highly sensitive approach for probing these interactions, but achieving the ultimate spectral resolution limit—known as the Fourier limit and determined by the natural lifetime of the molecule’s excited state—remains chal-lenging. This limitation is often attributed to surface-related issues such as contamination, defects, and dangling bonds.

In this work, we introduce a cryogenic sublimation method within a dilution refrigerator to prepare pristine anthracene (AC) crystal surfaces and deposit dibenzoterrylene (DBT) molecules onto them. Using this approach, we observe electronic transitions in single organic molecules adsorbed on the AC surface that reach the Fourier-limited linewidth at sub-Kelvin temperatures.

We further investigate inhomogeneous broadening, linewidth distributions, temperature-induced dephasing, spectral stability, and the spatial characteristics of molecules across the surface. Ad-ditionally, we compare the spectral properties of molecules in the gas phase, within bulk AC crys-tals, and at the crystal surface. These comparisons allow us to examine how different dielectric environments influence molecular spectral properties.

Our work facilitates the integration of high spatial resolution techniques with high-resolution laser spectroscopy at the single-molecule level.

(Vortrag auf Englisch))

Dem Vortrag schließt sich eine Diskussion von 15 Minuten an. Vortrag und Diskussion sind öffentlich. Diesen Verfahrensteilen folgt ein nicht öffentliches Rigorosum von 45 Minuten.