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TT: Fachverband Tiefe Temperaturen
TT 84: 2D Materials: Electronic structure, excitations, etc. III (joint session O/HL/TT)
TT 84.8: Vortrag
Donnerstag, 12. März 2026, 16:45–17:00, HSZ/0204
Ultrafast Momentum Dependent Relaxation Dynamics in TbTe3 — •Florian Denizer1, Noah Meyer2,3, Anisha Singh3, Ian R. Fisher3, Uwe Bovensiepen1, Zhi-Xun Shen2,3, and Patrick S. Kirchmann2 — 1Fakultät für Physik, Universität Duisburg-Essen — 2Department of Physics, Applied Physics and Stanford Synchrotron Radiation Laboratory, Stanford University — 3Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University
Rare-earth tritellurides (RTe3) form charge density waves (CDW) due to electronic instabilities at the Fermi-surface, because of an anisotropy of the crystal lattice between the two major in-plane crystal axes a and c. Unoccupied electronic states can be populated by ultrafast laser excitation. Electronic relaxation and coherent vibrational modes including the amplitude mode have been investigated by time and angle resolved photoelectron spectroscopy (tr-ARPES). Among the manifold of laser-driven processes, the one that is responsible for the electronic instability has not yet been identified. With this objective in mind we perform a tr-ARPES experiment on TbTe3 and investigate the momentum transfer along the a- and the c-axis as a function of excitation strength. At sufficiently low pump fluence below F = 0.3 mJ/cm2 we identify (quasi-)elastic scattering in the vicinity of the Fermi surface. In the talk we will discuss isotropic defect-induced elastic scattering and directed quasi-elastic scattering determined by the nesting vector. Funding through the DFG within SFB 1242 and through the DOE is gratefully acknowledged.
Keywords: Ultrafast; Rare-earth tritelluride; Charge density wave; electron relaxation; ARPES