Wave-vector-dependent electron-phonon coupling and the charge-density-wave transition in $\mathrm{TbT}{\mathrm{e}}_3$

Journal Article · Mon Jun 01 00:00:00 EDT 2015 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PhysRevB.91.235146· OSTI ID:1391824

Maschek, M.; Rosenkranz, S.; Heid, R.; Said, A. H.; Giraldo-Gallo, P.; Fisher, I. R.; Weber, F.

We present a high-energy-resolution inelastic x-ray scattering investigation of the soft phonon mode in the charge-density-wave (CDW) system TbTe3. We analyze our data based on lattice dynamical calculations using density-functional-perturbation theory and find clear evidence that strongly momentum-dependent electron-phonon coupling defines the periodicity of the CDW superstructure: Our experiment reveals strong phonon softening and increased phonon linewidths over a large part in reciprocal space adjacent to the CDW ordering vector q(CDW) = (0,0,0.3). Further, q(CDW) is clearly offset from the wave vector of (weak) Fermi surface nesting q(FS) = (0,0,0.25), and our detailed analysis indicates that electron-phonon coupling is responsible for this shift. Hence, we can add TbTe3, which was previously considered as a canonical CDW compound following the Peierls scenario, to the list of distinct charge-density-wave materials characterized by momentum-dependent electron-phonon coupling.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1391824
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 91, Issue 23; ISSN 1098-0121
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English