# Dzyaloshinskii-Moriya Spin Density by skew scattering

**Authors:** Adam B. Cahaya, Alejandro O. Leon  
**arXiv:** [2207.06842](https://arxiv.org/abs/2207.06842)  
**Date:** 2022-07-14  
**Summary page:** https://www.summarizepaper.com/en/paper/2207.06842v1/

## Key points

- The Dzyaloshinskii-Moriya interaction (DMI) is an anisotropic exchange coupling that helps understand spin textures.
- A recent study predicts the existence of an anisotropic conduction electron spin density in metals with heavy magnetic impurities.
- The newly discovered entity, called the Dzyaloshinskii-Moriya Spin Density (DM-SD), does not align with localized magnetic moments but is rotated due to spin-dependent skew scattering of heavy atoms.
- The DM-SD serves as a mediator for the DMI between magnetic atoms in metals and exhibits anisotropic characteristics.
- The DM-SD can be considered as an extension of the Rutherman-Kittel-Kasuya-Yoshida spin density, which describes isotropic couplings.
- A proposed model includes two localized magnetic moments within a free electron gas, with one possessing significant spin-orbit coupling due to its lanthanide nature.
- The strength and polarization of the DM-SD are controlled by this lanthanide spin, providing flexible control mechanisms for anisotropic couplings.
- This study offers valuable insights into conduction electron spins in metals with heavy magnetic impurities and opens up possibilities for understanding and manipulating anisotropic exchange couplings.

## Summary

The Dzyaloshinskii-Moriya interaction (DMI) is an anisotropic exchange coupling that has been instrumental in understanding the formation and dynamics of spin textures. In a recent study by Adam B. Cahaya and Alejandro O. Leon, an intriguing prediction is made regarding the existence of an anisotropic conduction electron spin density in metals containing heavy magnetic impurities. Unlike traditional spin densities, the polarization of this newly discovered entity, termed the Dzyaloshinskii-Moriya Spin Density (DM-SD), does not align with the localized magnetic moments. Instead, it is rotated due to the spin-dependent skew scattering of heavy atoms. This finding sheds light on a previously unexplored aspect of spin dynamics in materials with heavy impurities. Moreover, the DM-SD serves as a mediator for the DMI between magnetic atoms in metals. It plays a similar role to the spin density that couples distant magnetic impurities in metals but exhibits anisotropic characteristics. In fact, it can be considered as an extension of the Rutherman-Kittel-Kasuya-Yoshida spin density, which describes isotropic couplings. To investigate this phenomenon further, Cahaya and Leon propose a model comprising two localized magnetic moments within a free electron gas. One of these moments possesses a significant spin-orbit coupling due to its lanthanide nature. The strength and polarization of the DM-SD are controlled by this lanthanide spin, offering a promising avenue for flexible control mechanisms for anisotropic couplings. Overall, this study provides valuable insights into the behavior of conduction electron spins in metals with heavy magnetic impurities. The discovery and characterization of the DM-SD open up new possibilities for understanding and manipulating anisotropic exchange couplings in various materials systems.