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TT: Fachverband Tiefe Temperaturen
TT 39: Correlated Electrons: Charge Order
TT 39.6: Vortrag
Mittwoch, 20. März 2024, 11:00–11:15, H 3025
Comparative optical study of the CDW states in various TaS2 polymorphs — •Renjith Mathew Roy1, Maxim Wenzel1, Sudip Pal1, Vicky Hasse2, Claudia Felser2, Artem V. Pronin1, and Martin Dressel1 — 11. Physikalisches Institut, Universität Stuttgart, 70569 Stuttgart, Germany — 2Max-Planck-Institut für Chemische Physik fester Stoffe, 01187 Dresden, Germany
We report the temperature-dependent optical conductivity of the bulk transition-metal dichalcogenides 4Hb-TaS2, 2H- TaS2, and 6R-TaS2, studied in a broad energy range from 10 meV to 2.5 eV. These kagome-structured compounds possess a charge density wave (CDW) state below TCDW 22, 75, and 305 K, respectively. The presence of coexisting superconductivity and possible chiral CDW order, as well as the occurrence of topological flat bands in various polymorphs of TaS2, fueled the recent interest in their studies [1-4]. In all three compounds, we observe a common interband response above 100 meV and distinguishable signatures of band reconstruction below TCDW. Our compassion provides a broader picture of the CDW-formation mechanism via detecting the energy gaps and possible charge localization, emerging in these quasi-2D systems.
[1] A. Ribak et al., Sci. Adv. 6, eaax9480 (2020)
[2] S. Pal et al., Phys. B: Cond. Mat. 669 (2023) 415266.
[3] I. Guillamón et al., New J. Phys. 13 (2011) 103020.
[4] J. M. Lee et al., Phys. Rev. Lett. 124 (2020) 137002.
Keywords: Charge Density Wave; TaS2; Kagome; Infrared Spectroscopy; Flat bands