First-principles approach to correlated materials
The present proposal is a continuation from last year's project. We have now developed a GW+DMFT code and succeeded in performing a self-consistent GW+DMFT calculations on a prototype of correlated metals SrVO3, in collaboration with the group of Prof. Philipp Werner of the University of Fribourg, Switzerland. The work has now been published in Phys. Rev. B 94, 201106 (2016). We are now applying the developed code and scheme to some interesting systems to have a better understanding of the GW+DMFT theory. One prime target is the famous parent compound of the high -temperature superconductor La2CuO4. These calculations are expected to take a large amount of computing time due to the complex structure of the material. The other main project that will occupy our research activity this year is the calculations of the screened interaction and the Hubbad U in real space and time for a series of high-temperature superconductors. The aim of this study is to investigate the possibility of the formation of Cooper pairs purely from electronic origin, as opposed to non-electronic mediator such as phonons or spin-mediated mechanism. The screened interactions in space and time may give us a new insight into the mechanism of Cooper pairing. These calculations started a few months ago and will continue this year. The long-term goal is to use the resulting screened interactions to solve the Eliashberg equation for the gap equation.