Alternative route to charge density wave formation in multiband systems

作者：Eiter Hans Martin; Lavagnini Michela; Hackl Rudi^*; Nowadnick Elizabeth A; Kemper Alexander F; Devereaux Thomas P; Chu Jiun Haw; Analytis James G; Fisher Ian R; Degiorgi Leonardo

来源：Proceedings of the National Academy of Sciences, 2013, 110(1): 64-69.

DOI：10.1073/pnas.1214745110

• electron-phonon interactions
• nonconventional mechanism
• Raman spectroscopy
• solid-solid phase transitions

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 densitywave system ErTe3. 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.

• 出版日期2013-1-2