Noncollinear twisted RKKY interaction on the optically driven SnTe(001) surface

TL;DR

This paper investigates how weak optical driving influences the RKKY interaction between magnetic impurities on doped SnTe(001) surfaces, revealing noncollinear twisted interactions with potential for optical control of spin textures.

Contribution

It introduces a novel analysis of Floquet-driven RKKY interactions on SnTe surfaces, highlighting the role of spin-orbit hybridization and proposing optical control of doping and band structure.

Findings

Dominant $z$-component of XYZ-Heisenberg interaction.

Significant in-plane symmetric and asymmetric Dzyaloshinskii-Moriya terms.

Optical control can modify interactions and break electron-hole symmetry.

Abstract

The nontrivial spin texture on the (001) surface of topological crystalline insulator SnTe hosts exotic scientific importance and spintronic applications. Here, we study the effects of weak Floquet optical driving on the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between two magnetic impurities on a doped SnTe(001) surface. Due to peculiar spin-orbit hybridization, we find a noncollinear twisted RKKY interaction comprising XYZ-Heisenberg, symmetric in-plane, and asymmetric Dzyaloshinskii-Moriya (DM) terms. We see that contributions from the $z$ ($x$)-component of the XYZ-Heisenberg (DM) interaction are dominant for most parameters. The interactions, including DM terms that are responsible for interesting spin textures, require doping in most cases. We propose to modify the interactions in situ via optical control of band structure, and thereby doping. A notable aspect of this control protocol is breaking of electron-hole symmetry, which stems from the DM interaction.