Spin-polarized and possible pseudospin-polarized scanning tunneling microscopy in kagome metal FeSn

Abstract

Kagome Lattices provide a platform for studying competing quantum ground states. Lee and colleagues observed the pseudospin texture of FeSn in real space, deepening our understanding of the lattice symmetry-preserving tunneling process in Dirac materials. A kagome lattice (KL) is a two-dimensional atomic network comprising hexagons interspersed with triangles, which provides a fascinating platform for studying competing quantum ground states. The KL contains three atoms in a unit cell, and their degrees of freedom combine to yield Dirac bands and a flat band. Despite many studies to understand the flat band in KL, exploring the pseudospin of Dirac bands in KL has been scarce. In this paper, we suggest pseudospin-polarized scanning tunneling microscopy that is analogous to spin-polarized scanning tunneling microscopy. Using a pseudospin-polarized tip, we possibly observed the pseudospin texture of kagome metal FeSn in real space. Based on a simple tight-binding calculation, we further simulated the pseudospin texture of KL, confirming the geometric origin of pseudospin. This work potentially deepens our understanding of the lattice symmetry-preserving tunneling process in Dirac materials.