Álvaro Jiménez-Galán,National Research Council Canada (NRC). Max Born Institute
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Abstract: On-demand modification of quantum material properties is one of the holy grails of material science. Recently, the demonstrated feasibility to apply intense light fields, controlled at the level of individual oscillations, to 2D materials without optical damage, opened the opportunity to induce new properties that can be manipulated on the timescales of coherent electron motion. This technology is underpinned by the strong-field methods of coherent electron control, developed over thirty years in atomic gases. In this colloquium, I will briefly review the current state-of-the-art in strong-field control of electronic processes, as well as key quantum properties of 2D materials, such as topological phases and the valley degree of freedom, that can be potentially controlled on ultrafast timescales with current laser technology. I will demonstrate how application of strong-field concepts and technology to 2D materials allows: (i) to close the gap in a 2D semiconductor on few femtosecond timescales (1fs = 10-15s), inducing a light-controlled topological phase transition that can be read-out optically via high harmonic generation, (ii) ultrafast manipulation and reading of the valley degree of freedom. These works provide first steps towards the overarching goal of realizing petahertz switches of quantum properties. Yet, achieving this goal requires careful understanding of the laser-driven electron dynamics that unfold during the strong-field modification of the material. Time-resolved theory of strong laser-matter interaction in solids has marginally explored such dynamics, even at the independent particle level, while effects of many-body interactions on the strong-field optical response are largely uncharted. As an outlook, I will outline some of the steps that must be taken to realize the full potential of lightwave electronics. ** Refreshments served from 2:45pm – 3:00pm in PAS 218. Thank you. **