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arXiv · 1703.10589

Phase-ordering of charge density waves traced by ultrafast low-energy electron diffraction

S. Vogelgesang·G. Storeck·S. Schramm·K. Rossnagel·S. Schäfer·C. Ropers
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Abstract

We introduce ultrafast low-energy electron diffraction (ULEED) in backscattering for the study of structural dynamics at surfaces. Using a tip-based source of ultrashort electron pulses, we investigate the optically-driven transition between charge-density wave phases at the surface of 1T-TaS2. The large transfer width of the instrument allows us to employ spot-profile analysis, resolving the phase-ordering kinetics in the nascent incommensurate charge-density wave phase. We observe a coarsening that follows a power-law scaling of the correlation length, driven by the annihilation of dislocation-type topological defects of the charge-ordered lattice. Our work opens up the study of a wide class of structural transitions and ordering phenomena at surfaces and in low-dimensional systems.

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S. Vogelgesang, G. Storeck, S. Schramm, K. Rossnagel, S. Schäfer, C. Ropers. 2020-08-25. Phase-ordering of charge density waves traced by ultrafast low-energy electron diffraction. https://doi.org/10.1038/nphys4309

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