Collective modes in the charge-density wave state of K\(_{0.3}\)MoO\(_3\): The role of long-range Coulomb interactions revisited

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 li...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2023-08
Main Authors: Hansen, Max O, Palan, Yash, Hahn, Viktor, Thomson, Mark D, Warawa, Konstantin, Roskos, Hartmut G, Demsar, Jure, Pientka, Falko, Tsyplyatyev, Oleksandr, Kopietz, Peter
Format: Article
Language:English
Subjects:
Amplitudes
Charge density waves
Phonons
Temperature dependence
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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 K\(_{0.3}\)MoO\(_3\). With the exception of the lowest phase mode, the temperature dependence of the measured mode energies can be quantitatively described within a multi-phonon Fr\"{o}hlich model for generic electron-phonon interactions neglecting long-range Coulomb interactions.
ISSN:2331-8422
DOI:10.48550/arxiv.2303.08580