The Nanoscale and Quantum Phenomena Institute Seminar series presents Lian Li, Robert L. Carroll Professor of Physics, Department of Physics and Astronomy, West Virginia University, Morgantown, WV, on February 20 at 4:10 p.m. Seminars are held in ***WALTER 135*** and virtually on Teams. Refreshments provided. This week's speaker is hosted by Sergio Ulloa.

Visualizing symmetry-breaking electronic orders in epitaxial Kagome antiferromagnet FeSn film

Kagome is a Japanese term referring to a woven bamboo pattern composed of interlaced triangles, where each lattice point has four neighboring points. Materials with atoms arranged in this pattern exhibit emergent phenomena resulting from the interplay of frustration, spin-orbit coupling, and electron correlations. In this talk, I will present our recent work on the molecular beam epitaxy (MBE) growth and atomic-resolution imaging of symmetry breaking electronic orders in a model Kagome antiferromagnet, FeSn. This material consists of alternating planes of Fe3Sn Kagome and Sn honeycomb lattices, as confirmed by our in-situ low-temperature scanning tunneling microscopy. On the Fe3Sn Kagome layer, we observed stripe modulations, which can be tuned by an in-plane magnetic field, indicating a nematic electronic order. Furthermore, we imaged bound states of Sn vacancy defects and observed anomalous magnetic field dependence. Under an out-of-plane magnetic field, the bound states exhibit anomalous Zeeman shifts, where their energy shows blue shifts independent of the field direction. Under an in-plane magnetic field, the energy shift displays a two-fold oscillating behavior as a function of the azimuth angle. These results provide insight into the symmetry-breaking electronic orders arising from the entangled magnetic and charge degrees of freedom in magnetic Kagome materials.