Abstract
We report an experimental and theoretical study of the electron-phonon coupling for , a prototypical triangular lattice surface, closely related to , where recent experimental evidence has found superconductivity [X. Wu et al., Phys. Rev. Lett. 125, 117001 (2020)]. We concentrate our study on the () phase of that appears between 150 and 120 K and has a well-known geometry with a half-filled electronic band around the Fermi energy. We show that this surface presents a giant electron-phonon interaction that can be considered at least partially responsible for the different phases that this system shows at very low temperature. Our theoretical results indicate that indeed the electron-phonon interaction in is unusually large, since we find that , the electron mass enhancement for the half-filled band, is . This result is in good agreement with the experimental value obtained from high-resolution angle-resolved photoemission spectroscopy measurements, which yield .
- Received 1 April 2022
- Revised 30 November 2022
- Accepted 13 December 2022
DOI:https://doi.org/10.1103/PhysRevB.107.045303
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