Temperature-dependent reflectivity studies on the nonmagnetic kagome metal $RbV_3Sb_5$ in a broad energy range ($50--20000cm^-1$, equivalent to 6 meV--2.5 eV) down to 10 K are reported. Below $T_CDW=102$ K, the optical spectra demonstrate a prominent spectral-weight transfer from low to higher energies as the fingerprint of the charge-density-wave (CDW) formation with the opening of a partial gap. A detailed analysis reveals two energy scales of respectively $\sim800 cm^-1$ (100 meV) and $360cm^-1$ (45 meV), the latter visible below 50 K only. Additionally, two modes at respectively $160cm^-1$ (20 meV) and $430cm^-1$ (53 meV) can be traced both above and below $T_CDW$. They show strong anomalies already above $T_CDW$ with a further renormalization across the transition, suggesting the importance of the electron-phonon coupling in $RbV_3Sb_5$ in both normal and CDW states. While the $160cm^-1$ mode can be attributed to the $E_1u$ phonon, the $430cm^-1$ mode could not be reproduced in our phonon calculations. The antiresonance nature of this mode suggests a nontrivial electron-phonon coupling in $RbV_3Sb_5$. A distinct localization peak observed at all temperatures signals damped electron dynamics, whereas the reduced Drude spectral weight manifests moderate deviations from the band picture in $RbV_3Sb_5$.
%0 Journal Article
%1 PhysRevB.105.245123
%A Wenzel, M.
%A Ortiz, B. R.
%A Wilson, S. D.
%A Dressel, M.
%A Tsirlin, A. A.
%A Uykur, E.
%D 2022
%I American Physical Society
%J Phys. Rev. B
%K charge-density-waves non-magnetic-kagome-metal superconductivity
%N 24
%P 245123
%R 10.1103/PhysRevB.105.245123
%T Optical study of RbV3Sb5: Multiple density-wave gaps and phonon anomalies
%U https://link.aps.org/doi/10.1103/PhysRevB.105.245123
%V 105
%X Temperature-dependent reflectivity studies on the nonmagnetic kagome metal $RbV_3Sb_5$ in a broad energy range ($50--20000cm^-1$, equivalent to 6 meV--2.5 eV) down to 10 K are reported. Below $T_CDW=102$ K, the optical spectra demonstrate a prominent spectral-weight transfer from low to higher energies as the fingerprint of the charge-density-wave (CDW) formation with the opening of a partial gap. A detailed analysis reveals two energy scales of respectively $\sim800 cm^-1$ (100 meV) and $360cm^-1$ (45 meV), the latter visible below 50 K only. Additionally, two modes at respectively $160cm^-1$ (20 meV) and $430cm^-1$ (53 meV) can be traced both above and below $T_CDW$. They show strong anomalies already above $T_CDW$ with a further renormalization across the transition, suggesting the importance of the electron-phonon coupling in $RbV_3Sb_5$ in both normal and CDW states. While the $160cm^-1$ mode can be attributed to the $E_1u$ phonon, the $430cm^-1$ mode could not be reproduced in our phonon calculations. The antiresonance nature of this mode suggests a nontrivial electron-phonon coupling in $RbV_3Sb_5$. A distinct localization peak observed at all temperatures signals damped electron dynamics, whereas the reduced Drude spectral weight manifests moderate deviations from the band picture in $RbV_3Sb_5$.
@article{PhysRevB.105.245123,
abstract = {Temperature-dependent reflectivity studies on the nonmagnetic kagome metal ${\mathrm{RbV}}_{3}{\mathrm{Sb}}_{5}$ in a broad energy range ($50--20000{\mathrm{cm}}^{\ensuremath{-}1}$, equivalent to 6 meV--2.5 eV) down to 10 K are reported. Below ${T}_{\mathrm{CDW}}=102$ K, the optical spectra demonstrate a prominent spectral-weight transfer from low to higher energies as the fingerprint of the charge-density-wave (CDW) formation with the opening of a partial gap. A detailed analysis reveals two energy scales of respectively $\ensuremath{\sim}800 {\mathrm{cm}}^{\ensuremath{-}1}$ (100 meV) and $360{\mathrm{cm}}^{\ensuremath{-}1}$ (45 meV), the latter visible below 50 K only. Additionally, two modes at respectively $160{\mathrm{cm}}^{\ensuremath{-}1}$ (20 meV) and $430{\mathrm{cm}}^{\ensuremath{-}1}$ (53 meV) can be traced both above and below ${T}_{\mathrm{CDW}}$. They show strong anomalies already above ${T}_{\mathrm{CDW}}$ with a further renormalization across the transition, suggesting the importance of the electron-phonon coupling in ${\mathrm{RbV}}_{3}{\mathrm{Sb}}_{5}$ in both normal and CDW states. While the $160{\mathrm{cm}}^{\ensuremath{-}1}$ mode can be attributed to the ${E}_{1u}$ phonon, the $430{\mathrm{cm}}^{\ensuremath{-}1}$ mode could not be reproduced in our phonon calculations. The antiresonance nature of this mode suggests a nontrivial electron-phonon coupling in ${\mathrm{RbV}}_{3}{\mathrm{Sb}}_{5}$. A distinct localization peak observed at all temperatures signals damped electron dynamics, whereas the reduced Drude spectral weight manifests moderate deviations from the band picture in ${\mathrm{RbV}}_{3}{\mathrm{Sb}}_{5}$.},
added-at = {2022-06-20T08:28:31.000+0200},
author = {Wenzel, M. and Ortiz, B. R. and Wilson, S. D. and Dressel, M. and Tsirlin, A. A. and Uykur, E.},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2f4d155324786b1fb2c733c12d5337d17/dr.helgakumric},
doi = {10.1103/PhysRevB.105.245123},
interhash = {b1d5a97fd0e55ba4e72dbd6064d3dc38},
intrahash = {f4d155324786b1fb2c733c12d5337d17},
journal = {Phys. Rev. B},
keywords = {charge-density-waves non-magnetic-kagome-metal superconductivity},
month = jun,
number = 24,
numpages = {13},
pages = 245123,
publisher = {American Physical Society},
timestamp = {2022-06-20T06:28:31.000+0200},
title = {Optical study of RbV3Sb5: Multiple density-wave gaps and phonon anomalies},
url = {https://link.aps.org/doi/10.1103/PhysRevB.105.245123},
volume = 105,
year = 2022
}
