Electronic structure and topology across $T_c$ in magnetic Weyl semimetal Co${}_3$Sn${}_2$S${}_2$

Abstract

Co${}_3$Sn${}_2$S${}_2$ is a magnetic Weyl semimetal, in which ferromagnetic ordering at 177K is predicted to stabilize Weyl points. We perform temperature and spatial dependent angle--resolved photoemission spectroscopy measurements through the Curie temperature ($T_c$), which show large band shifts and renormalization concomitant with the onset of magnetism. We argue that Co${}_3$Sn${}_2$S${}_2$ evolves from a Mott ferromagnet below $T_c$ to a correlated metallic state above $T_c$. To understand the magnetism, we derive a tight-binding model of Co-$3d_{x^2-y^2}$ orbitals on the kagome lattice. At the filling obtained by first-principles calculations, this model reproduces the ferromagnetic ground state, and results in the reduction of Coulomb interactions due to cluster effects. Using a disordered local moment simulation, we show how this reduced Hubbard-$U$ leads to a collapse of the bands across the magnetic transition, resulting in a correlated state which carries associated characteristic photoemission signatures that are distinct from those of a simple lifting of exchange splitting. The behavior of topology across $T_c$ is discussed in the context of this description of the magnetism.

12 pages, 8 figures

References in corpus (11)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Dirac materials
• Quantum Monte Carlo Impurity Solver for Cluster DMFT and Electronic Structure Calculations in Adjustable Base
• Negative flat band magnetism in a spin-orbit coupled correlated kagome magnet
• A precise method for visualizing dispersive features in image plots
• Intrinsic anomalous Hall effect in Ni-substituted magnetic Weyl semimetal Co3Sn2S2
• Time-reversal symmetry breaking driven topological phase transition in EuB${}_6$
• Topological Phase Transition in a Magnetic Weyl Semimetal
• Revealing the chemical bonding in adatoms arrays via machine learning of 3D scanning tunneling spectroscopy data
• Spin dynamics of a magnetic Weyl semimetal Sr${}_{1-x}$Mn${}_{1-y}$Sb${}_2$

Cited by in corpus (12)

• Transport, refraction and interface arcs in junctions of Weyl semimetals
• Electronic structure evolution of the magnetic Weyl semimetal Co${}_3$Sn${}_2$S${}_2$ with hole and electron doping
• Pressure-Driven Magneto-Topological Phase Transition in a magnetic Weyl semimetal
• Microscopic origins and stability of the ferromagnetism in Co${}_3$Sn${}_2$S${}_2$
• Correlation driven near-flat band Stoner excitations in a Kagome magnet
• Linear response theories for interatomic exchange interactions
• Hubbard model on the kagome lattice with time-reversal invariant flux and spin-orbit coupling
• Topological phase transitions in strongly correlated systems: application to Co${}_3$Sn${}_2$S${}_2$
• Absence of backscattering in Fermi-arc-mediated conductivity of topological Dirac semimetal Cd${}_3$As${}_2$
• Reexamining Circular Dichroism in Photoemission From a Topological Insulator
• In-plane Antiferromagnetism in Ferromagnetic Kagome Semimetal Co3Sn2S2
• Mesoscale variations of chemical and electronic landscape on the surface of Weyl semimetal Co${}_3$Sn${}_2$S${}_2$ visualized by ARPES and XPS