Condensed Matter Physics in the Alps: Geometric Frustration, Topology, Flat Bands, and Correlation in Kagome and Van der Waals Systems

Session

Tuesday Afternoon Session, Chair R. McQueeney

6 Jan 2026, 17:00

Saas Fee

48. Terahertz-frequency magnons and chiral phonons in a kagome ferromagnetic Weyl semimetal

Luyi Yang (Tsinghua University)

06/01/2026, 17:00

Kagome experimental

Invited talk (by invitation only)

Kagome lattice provides a rich platform for exploring novel quantum states, emerging from the interplay between its frustrated corner-sharing triangular geometry and intriguing electronic structure. Co3Sn2S2 is a kagome lattice ferromagnet, exhibiting a unique interplay between its electronic wavefunction topology and magnetic spin configuration. This interaction results in several intriguing...

62. Unconventional magnetism in kagome magnet Co3Sn2S2

Yona Soh

06/01/2026, 17:35

Kagome experimental

Invited talk (by invitation only)

Shandite Co3Sn2S2 has been synthesized and studied extensively, but there is still a lack of consensus regarding the magnetic ground state. Since its discovery, it has been considered a ferromagnet with c-axis as its easy axis. However, recently, there has been reports of exchange bias based on magnetometry and anomalous Hall effect attributed to spin glass and presence of antiferromagnetism...

65. Neutron scattering studies of two kagome magnets

Romain Franck Sibille (PSI - Paul Scherrer Institut)

06/01/2026, 18:10

Kagome experimental

Invited talk (by invitation only)

In a first part I will summarise results of an experimental study to unravel the magnetic ground state and interactions in Co$_3$Sn$_2$S$_2$, conducted with colleagues from PSI (Yona Soh) and the ILL (David Tam). By exploring the magnetic interactions to moderately high energies and using non-invasive probes to measure the magnetic ground state, we discover that the spin wave spectrum and...