Chiral orbital current driven topological Hall effect in Mn3Si2Te6

TL;DR

This paper reveals that in Mn3Si2Te6, the topological Hall effect originates from chiral orbital currents rather than spin textures, highlighting the role of orbital textures in topological transport in 2D magnets.

Contribution

It demonstrates that orbital textures can produce a topological Hall effect and colossal magnetoresistance, offering a new mechanism for dissipationless transport in layered magnetic materials.

Findings

THE signal increases in nanoflakes compared to bulk

THE disappears with increasing current

Strong correlation between CMR and THE

Abstract

Chiral orbital current (COC) plays a crucial role in governing the magnetization and transport behaviour in the layered ferrimagnetic nodal-line semiconductor Mn3Si2Te6. Here, we observe that the topological Hall effect (THE), typically attributed to Berry curvature from chiral spin textures, originates from COC, which produces an emergent magnetic field for conduction electrons due to its real-space orbital textures. We find that the THE signal strengthens as we move down from bulk to nanoflakes, but tends to disappear with increasing current, along with the disappearance of the COC state. We also demonstrate a strong correlation between the colossal magnetoresistance (CMR) and the observed THE, suggesting that large Berry curvature and topological transport can arise purely from orbital degrees of freedom, providing a new platform for engineering dissipationless transport in 2D magnets.