Field-Controlled Topological States in Atomically thin ScV₆Sn₆ Kagome Metal

We investigate the topological properties of monolayer ScV₆Sn₆ kagome metal^[1] using first-principles calculations. Unlike its paramagnetic bulk form, the single-layer system exhibits spontaneous magnetization (~0.86 μB/atom) with an ordering temperature near 89 K. The electronic structure displays Weyl-type band crossings near the chemical potential, which are gapped by spin-orbit interactions and yield a unit Chern invariant with chiral boundary modes. Berry curvature integration reveals an intrinsic Hall response of 257 Ω⁻¹cm⁻¹, comparable to other magnetic two-dimensional topological systems. Crucially, perpendicular electric fields enable topological phase control: the nontrivial character remains stable below 0.40 eV/Å but transitions to a trivial metallic state at this threshold, where edge modes disappear and the Chern number vanishes. 2D ScV₆Sn₆ emerges as a promising platform for electrically tunable topological phenomena, relevant to reconfigurable quantum technologies and voltage-controlled spintronic applications.