The cs2t group focuses on the development of novel theoretical and computational techniques to investigate the electronic and structural dynamics of condensed matter from first principles, i.e., starting from the fundamental equations of quantum mechanics. Goal of our research consists in identifying new properties, functions, and quantum phenomena which may be established in solids upon exposure to ultrashort light pulses. The group activity primarily concentrates on the area of ultrafast dynamics, theoretical spectroscopy, and 2D materials.
The advent of ultrashort laser pulses has opened new directions to achieve properties on demand in quantum matter. Our approach to investigate the ultrafast electronic and structural dynamics of photo-excited materials combines (i) Green’s function techniques, (ii) the first-principles theory of the electron-phonon interaction, and (iii) theoretical approaches for the time-propagation, as e.g., the time-dependent Boltzmann equation. By facilitating the interpretation of pump-probe spectroscopy measurements, these techniques complement purely experimental investigations, enabling a strong synergy with experimental groups in field of ultrafast science.
Spectroscopy techniques provide a powerful tool to directly probe fundamental interactions between the constituents of matter. In the cs2t group, we employ and develop state-of-the-art theoretical approaches to complement experimental investigations and predict, in silico, novel emergent phenomena in spectroscopy. In particular, by accounting explicitly for the interplay between ionic and electronic excitations (phonons, plasmons, excitons), collective phenomena in solids and their fingerprints in spectroscopy experiments can be described realistically and accurately entirely from first principles.
The interplay of charge confinement, reduced dielectric screening, and strong light-matter coupling in 2D and layered materials underpins a rich spectrum of emergent phenomena and quasiparticles, including the formation of excitons, trions, polarons, polaritons, and superconductivity. At variance with ordinary bulk materials, these phenomena can further be tuned via cavity embedding, circular dichroism, gating, nano-structuring, substrate engineering, and doping. In the cs2t group, we investigate how these degrees of freedom influence the opto-electronic properties of 2D and layered materials. We are particularly interested in the predicting the conditions necessary for the establishment of strong coupling regimes, whereby the fundamental interactions among the constituents of matter may alter profoundly its electronic and vibrational properties, leading to the formation of new forms of quasiparticles.
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