First-principles Approaches for Strongly Correlated Many-body Systems
일 시 : 2021년 09월 15일 수요일 16:30
연 사 : 강 병 균 교수 ( University of Nevada, USA )
장 소 : 온라인 진행 (https://us02web.zoom.us/j/87648119834?pwd=S3k5bHk0UWxmdFpMR3IyVkNNQngvQT09)
HOST : 조 준 형 교수님
초 록
Understanding the many-body effects in strongly correlated systems is one of the grand challenges for condensed matter physics. In this talk, I will present brief history of manybody methods and recently developed ab initio linearized quasi-particle self-consistent GW (LQSGW) + dynamical mean filed theory (DMFT) methodology. Then, two case studies will be demonstrated. First, we investigated the origin of two-peak structure in the valence band photoemission spectra of an archetypical strongly-correlated material, late-transition metal NiO. We show that the two-peak structure is shown to be driven by the concerted effect of antiferromagnetic ordering and inter-site electron hopping. Second, regarding high temperature superconductor infinite-layer nickelate Nd1−xSrxNiO, we found that onsite Hund’s coupling in Ni d orbitals gives rise to multiple signatures of Hund’s metallic phase in Ni d subshell. I will also introduce recent progress on the exploration of the Kondo effect in heavy-fermions using DMFT method.