CDW phases of rare-earth Tritellurides from first principles

The rare-earth tri-tellurides, RTe3 exhibit many phases, such as antiferromagnetic and charge-density-wave (CDW) order at different temperatures. The phase boundary also depends sensitively on the size of the rare-earth ion. There has been debate as to whether or not the CDW order can be predicted by zero-temperature DFT band structure properties such as its Fermi surface nesting. In this work, we perform the Fermi surface, the charge susceptibility, and phonon calculations in RTe3 based on DFT and DFPT methods. One challenge of this work is the difficulty of performing DFT and DFPT on a very fine k-mesh. Here, we generate electron and phonon band structures on a very fine k-mesh by interpolating them using Maximally-Localized Wannier Functions obtained from first-principles, and diagonalizing them for billions of k-points using a GPU algorithm. We also compute the charge susceptibility dressed by the electron-phonon interaction obtained from the EPW package across different rare-earth ions (R=La-Lu) and analyze the progression of susceptibility peaks as a function of R, comparing with experiment.