Abstract
In this chapter, we report a rare atom-like interaction between excitons in monolayer WS2, measured using ultrafast absorption spectroscopy. At increasing excitation density, the exciton resonance energy exhibits a pronounced redshift followed by an anomalous blueshift. Using both material-realistic computation and phenomenological modeling, we attribute this observation to plasma effects and an attraction-repulsion crossover of the exciton-exciton interaction that mimics the Lennard-Jones potential between atoms. Our experiment demonstrates a strong analogy between excitons and atoms with respect to inter-particle interaction, which holds promise to pursue the predicted liquid and crystalline phases of excitons in two-dimensional materials.
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Sie, E.J. (2018). Lennard-Jones-Like Potential of 2D Excitons in Monolayer WS2 . In: Coherent Light-Matter Interactions in Monolayer Transition-Metal Dichalcogenides. Springer Theses. Springer, Cham. https://doi.org/10.1007/978-3-319-69554-9_7
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DOI: https://doi.org/10.1007/978-3-319-69554-9_7
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