Harnessing topology and correlations from singularities in 3d-kagome metals.
일 시 : 2021년 07월 22일 목요일 16:00
연 사 : 강 민 구 박사 (Max Planck POSTECH Korea Research Initiative)
장 소 : 온라인 진행 ( https://us02web.zoom.us/j/89486593248?pwd=bW5QMWMxckdSV1l6UmNKOGMva0xHQT09 , 줌회의 ID: 894 8659 3248 )
HOST : 신 상 진 교수님
초 록
Kagome lattice is a network of corner-sharing triangles that has been studied extensively as a platform for novel quantum magnetic states. In metallic case, the symmetry of kagome lattice protects three singularities in its band structure including Dirac fermions at the Brillouin zone corner K, van Hove singularity at the zone edge M, and flat band across the whole Brillouin zone. If properly combined with spin-orbit coupling, magnetism, and strong electronic interactions, these unique singularities in the kagome lattice represent a rich potential to realize nontrivial topological and correlated many-body ground states including Chern insulators, magnetic Weyl semimetals, fractional quantum Hall effect, chiral density waves, and unconventional superconductivity.
In this talk, I will review the recent material realizations of such exotic electronic states in a series of 3d-transition metal-based kagome compounds. These include Dirac fermion-induced Chern insulating phase and intrinsic anomalous Hall conductivity in Fe3Sn2 [1,2], flat band-induced Stoner magnetism, nontrivial Z2 topology, and non-Fermi liquid behavior in (Fe,Co)Sn and Ni3In [3-6], and van Hove singularity-induced chiral charge order and unconventional superconductivity in (K,Rb,Cs)V3Sb5 [7,8]. These successful realizations highlight 3d-kagome metals as a promising opportunity to engineer novel emergent phases of matter at the crossroad between strongly correlated physics and electronic topology.