Collective modes in the charge-density wave state of KMoO: The role of long-range Coulomb interactions revisited
arXiv:2303.08580 · doi:10.1103/PhysRevB.108.045148
Abstract
We re-examine the effect of long-range Coulomb interactions on the collective amplitude and phase modes in the incommensurate charge-density-wave ground state of quasi-one-dimensional conductors. Using an effective action approach we show that the longitudinal acoustic phonon protects the gapless linear dispersion of the lowest phase mode in the presence of long-range Coulomb interactions. Moreover, in Gaussian approximation, amplitude fluctuations are not affected by long-range Coulomb interactions. We also calculate the collective mode dispersions at finite temperatures and compare our results with the measured energies of amplitude and phase modes in KMoO. With the exception of the lowest phase mode, the temperature dependence of the measured mode energies can be quantitatively described within a multi-phonon Fröhlich model for generic electron-phonon interactions neglecting long-range Coulomb interactions.
References in corpus (8)
- Eliashberg theory of phonon-mediated superconductivity -- when it is valid and how it breaks down
- Breakdown of the Migdal-Eliashberg theory and a theory of lattice-fermionic superfluidity
- Observation of the massive Lee-Fukuyama phason in a charge density wave insulator
- Charge ordering and magnetism in quarter-filled Hubbard-Holstein model
- Observing separate spin and charge Fermi seas in a strongly correlated one-dimensional conductor
- Limits of Eliashberg Theory and Bounds for Superconducting Transition Temperature
- Combined investigation of collective amplitude and phase modes in a quasi-one-dimensional charge-density-wave system over a wide spectral range
- Splitting of Fermi point of strongly interacting electrons in one dimension: A nonlinear effect of spin-charge separation