Faeth, BD and Xie, S and Yang, S and Kawasaki, JK and Nelson, JN and Zhang, S and Parzyck, C and Mishra, P and Li, C and Jozwiak, C and Bostwick, A and Rotenberg, E and Schlom, DG and Shen, KM (2021) Interfacial Electron-Phonon Coupling Constants Extracted from Intrinsic Replica Bands in Monolayer FeSe/SrTi O3. In: Physical Review Letters, 127 (1).
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Abstract
The observation of replica bands by angle-resolved photoemission spectroscopy has ignited interest in the study of electron-phonon coupling at low carrier densities, particularly in monolayer FeSe/SrTiO3, where the appearance of replica bands has motivated theoretical work suggesting that the interfacial coupling of electrons in the FeSe layer to optical phonons in the SrTiO3 substrate might contribute to the enhanced superconducting pairing temperature. Alternatively, it has also been recently proposed that such replica bands might instead originate from extrinsic final state losses associated with the photoemission process. Here, we perform a quantitative examination of replica bands in monolayer FeSe/SrTiO3, where we are able to conclusively demonstrate that the replica bands are indeed signatures of intrinsic electron-boson coupling, and not associated with final state effects. A detailed analysis of the energy splittings and relative peak intensities between the higher-order replicas, as well as other self-energy effects, allows us to determine that the interfacial electron-phonon coupling in the system corresponds to a value of λ=0.19±0.02, providing valuable insights into the enhancement of superconductivity in monolayer FeSe/SrTiO3. The methodology employed here can also serve as a new and general approach for making more rigorous and quantitative comparisons to theoretical calculations of electron-phonon interactions and coupling constants. © 2021 American Physical Society.
| Item Type: | Journal Article |
|---|---|
| Publication: | Physical Review Letters |
| Publisher: | American Physical Society |
| Additional Information: | The copyright for this article belongs to the Authors. |
| Keywords: | Electron correlations; Electron-phonon interactions; Electrons; Iron compounds; Monolayers; Photoelectron spectroscopy; Selenium compounds; Strontium titanates; Titanium compounds, Angle resolved photoemission spectroscopy; Electron phonon couplings; Electron-phonon coupling constant; Interfacial couplings; Quantitative comparison; Relative peak intensity; Superconducting pairing; Theoretical calculations, Iron-based Superconductors |
| Department/Centre: | Division of Physical & Mathematical Sciences > Physics |
| Date Deposited: | 16 Sep 2021 08:59 |
| Last Modified: | 16 Sep 2021 08:59 |
| URI: | http://eprints.iisc.ac.in/id/eprint/69601 |
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