How Strong, Local Correlation Modifies Electron-Phonon Coupling in Correlated Metals: A Density Functional Theory+Dynamical Mean Field Theory Study

Strong electron-electron interactions are known to significantly modify electron-phonon (e-ph) interactions, but this effect is challenging to calculate directly in real materials. Here we present a definition of the e-ph coupling strength applicable beyond a band theory description and calculate this coupling using first principles finite difference Density Functional Theory + Dynamical Mean Field Theory (DFT+DMFT). We present results for select representative phonon modes in two materials of interest: the three-orbital correlated metal SrVO3 and the infinite layer cuprate CaCuO2. We find that correlation effects significantly modify e-ph coupling strengths in a mode dependent manner, and gains a significant dependence on the electronic frequency. We also calculate the corresponding frequency-dependent e-ph scattering associated with these modes, which we show is modified by the electronic correlation.