Dresden 2026 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 86: Surface dynamics
O 86.5: Vortrag
Donnerstag, 12. März 2026, 16:15–16:30, HSZ/0403
Control and thermal evolution of commensurate charge-density wave order in 1H-NbSe2 — •Clara Pfister1,2, Alexander Bäder3,4, Laura Pätzold1, Tobias Wichmann3, Felix Lüpke3,4, Mariana Rossi5, and Tim O. Wehling1,2 — 1I. Institut für Theoretische Physik, Universität Hamburg — 2The Hamburg Centre for Ultrafast Imaging — 3Peter-Grünberg-Institut, Forschungszentrum Jülich — 4II. Physikalisches Institut, Universität zu Köln — 5MPI für Struktur und Dynamik der Materie, Hamburg
Charge-density waves (CDWs) are symmetry-broken ground states arising from electron-lattice interactions and offer a platform to study tunable ordered phases in quasi two-dimensional materials. Using ab initio calculations and a downfolding approach [1], we investigate how biaxial tensile strain and electron doping affect CDW order in 1H-NbSe2. In both cases, a transition from the native 3×3 to a competing 2×2 CDW ground state is induced. The strain-induced 2×2 CDW is supported by experimental data of monolayer 1H-NbSe2 flakes that are rotated with respect to the underlying bulk NbSe2. By constructing phase diagrams, we are able to identify the strain- and doping-induced boundaries between the competing CDW ground states. Moreover, by performing molecular dynamics (MD) simulations, we find that strain-induced 2×2 order persists up to TCDW ≈ 10 K, whereas the doping-induced 2×2 CDW is thermally much less stable. Our MD results furthermore suggest that nuclear entropy is the driving mechanism in the melting process of the CDW.
[1] A. Schobert et al., SciPost Phys. 16, 046 (2024)
Keywords: NbSe2; Charge-density waves; Downfolding; Molecular dynamics