Signatures of Weyl fermion annihilation in a correlated kagome magnet

Abstract

The manipulation of topological states in quantum matter is an essential pursuit of fundamental physics and next-generation quantum technology. Here we report the magnetic manipulation of Weyl fermions in the kagome spin-orbit semimetal Co${}_3$Sn${}_2$S${}_2$, observed by high-resolution photoemission spectroscopy. We demonstrate the exchange collapse of spin-orbit-gapped ferromagnetic Weyl loops into paramagnetic Dirac loops under suppression of the magnetic order. We further observe that topological Fermi arcs disappear in the paramagnetic phase, suggesting the annihilation of exchange-split Weyl points. Our findings indicate that magnetic exchange collapse naturally drives Weyl fermion annihilation, opening new opportunities for engineering topology under correlated order parameters.

Accepted version. Comments welcome! Early version of this manuscript first submitted in January 2020. See also: arXiv:2005.02400, Co3Sn2S2

References in corpus (8)

• Phase transition between the quantum spin Hall and insulator phases in 3D: emergence of a topological gapless phase
• Discovery of a quantum limit Chern magnet TbMn6Sn6
• Negative flat band magnetism in a spin-orbit coupled correlated kagome magnet
• Discovery of Weyl fermion semimetals and topological Fermi arc states
• Weyl, Dirac and high-fold chiral fermions in topological quantum materials
• Observation of Weyl fermions in a magnetic non-centrosymmetric crystal
• Intrinsic anomalous Hall effect in Ni-substituted magnetic Weyl semimetal Co3Sn2S2
• Topological surface superconductivity in doped Weyl loop materials

Cited by in corpus (17)

• Topological kagome magnets and superconductors
• Plethora of tunable Weyl fermions in kagome magnet Fe3Sn2 thin films
• What's knot to like? Observation of a linked loop quantum state
• Endless Dirac nodal lines in kagome-metal Ni3In2S2
• Intrinsic Magnetic Topological Materials
• 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
• Electronic band structures of topological kagome materials
• Light-induced anomalous Hall conductivity in massive 3D Dirac semimetal Co${}_3$Sn${}_2$S${}_2$
• Nodal line resonance generating the giant anomalous Hall effect of Co${}_3$Sn${}_2$S${}_2$
• Engineering holographic flat fermionic bands
• Enhancement of Spin-Charge Conversion Efficiency for Co${}_3$Sn${}_2$S${}_2$ across Transition from Paramagnetic to Ferromagnetic Phase
• A topological Hund nodal line antiferromagnet
• Emergent Weyl Fermions in an Orbital Multipolar Ordering Phase
• Tunable Anomalous Hall Effect in a Kagome Ferromagnetic Weyl Semimetal
• Nature of magnetic exchange interactions in kagome antiferromagnets FeGe and FeSn
• Effect of superconductivity by Nb and V substitution in kagome CaPd5