title: Alternative route to charge density wave formation in multiband systems.
abstract: Charge and spin density waves, periodic modulations of the electron, and magnetization densities, respectively, are among the most abundant and nontrivial low-temperature ordered phases in condensed matter. The ordering direction is widely believed to result from the Fermi surface topology. However, several recent studies indicate that this common view needs to be supplemented. Here, we show how an enhanced electron-lattice interaction can contribute to or even determine the selection of the ordering vector in the model charge density wave system ErTe(3). Our joint experimental and theoretical study allows us to establish a relation between the selection rules of the electronic light scattering spectra and the enhanced electron-phonon coupling in the vicinity of band degeneracy points. This alternative proposal for charge density wave formation may be of general relevance for driving phase transitions into other broken-symmetry ground states, particularly in multiband systems, such as the iron-based superconductors.
authors.affiliation: Walther Meissner Institut,  Bayerische Akademie der Wissenschaften, 85748 Garching,  Germany.
authors.forename: Hans-Martin
authors.initials: HM
authors.lastname: Eiter
authors.forename: Michela
authors.initials: M
authors.lastname: Lavagnini
authors.forename: Rudi
authors.initials: R
authors.lastname: Hackl
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Nowadnick
authors.forename: Alexander F
authors.initials: AF
authors.lastname: Kemper
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Devereaux
authors.forename: Jiun-Haw
authors.initials: JH
authors.lastname: Chu
authors.forename: James G
authors.initials: JG
authors.lastname: Analytis
authors.forename: Ian R
authors.initials: IR
authors.lastname: Fisher
authors.forename: Leonardo
authors.initials: L
authors.lastname: Degiorgi
mesh_terms: D055590:Electromagnetic Phenomena; D004583:Electrons; D004871:Erbium / Q000737:chemistry; D008280:Magnetics; D044367:Phase Transition / Q000528:radiation effects*; D013059:Spectrum Analysis, Raman; D013691:Tellurium / Q000737:chemistry
chemical_list: D004871:Erbium; D013691:Tellurium