Abstract
We report the observation of multiple phonon satellite features in ultrathin superlattices of the form using resonant inelastic x-ray scattering (RIXS). As the values of and vary, the energy loss spectra show a systematic evolution in the relative intensity of the phonon satellites. Using a closed-form solution for the RIXS cross section, we extract the variation in the electron-phonon coupling strength as a function of and . Combined with the negligible carrier doping into the layers, these results indicate that the tuning of the electron-phonon coupling can be effectively decoupled from doping. This work both showcases a feasible method to extract the electron-phonon coupling in superlattices and unveils a potential route for tuning this coupling, which is often associated with superconductivity in -based systems.
- Received 20 June 2018
- Revised 15 October 2018
DOI:https://doi.org/10.1103/PhysRevLett.121.236802
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