Signatures of weyl fermion annihilation in a correlated kagome magnet

DOI: 10.1103/PhysRevLett.127.256403

Authors: Ilya Belopolski (Princeton University; RIKEN Center for Emergent Matter Science (CEMS)) , Tyler A. Cochran (Princeton University) , Xiaoxiong Liu (University of Zurich) , Zi-Jia Cheng (Princeton University) , Xian P. Yang (Princeton University) , Zurab Guguchia (Princeton University; Paul Scherrer Institute) , Stepan S. Tsirkin (University of Zuric) , Jia-Xin Yin (Princeton University) , Praveen Vir (Max Planck Institute for Chemical Physics of Solids) , Gohil S. Thakur (Max Planck Institute for Chemical Physics of Solids; Technische Universitat) , Songtian S. Zhang (Princeton University) , Junyi Zhang (Princeton University) , Konstantine Kaznatcheev (National Synchrotron Light Source II) , Guangming Cheng (Princeton University) , Guoqing Chang (Nanyang Technological University) , Daniel Multer (Princeton University) , Nana Shumiya (Princeton University) , Maksim Litskevich (Princeton University) , Elio Vescovo (National Synchrotron Light Source II) , Timur K. Kim (Diamond Light Source) , Cephise Cacho (Diamond Light Source) , Nan Yao (Princeton University) , Claudia Felser (Max Planck Institute for Chemical Physics of Solids) , Titus Neupert (University of Zurich) , M. Zahid Hasan (Princeton University; Lawrence Berkeley National Laboratory)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review Letters , VOL 127

State: Published (Approved)
Published: December 2021
Diamond Proposal Number(s): 17924 , 19313

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.

Journal Keywords: Ferromagnetism; Topological materials; Semimetals; Angle-resolved photoemission spectroscopy

Diamond Keywords: Ferromagnetism

Subject Areas: Physics, Materials


Instruments: I05-ARPES

Other Facilities: 21-ID-1 (ESM-ARPES) at National Synchrotron Light Source II

Added On: 25/12/2021 07:35

Discipline Tags:

Quantum Materials Physics Hard condensed matter - structures Magnetism Materials Science

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES)