Probing Weyl-mediated spherical spin texture in SmAlSi

Lasin Abdul Rahman Thaivalappil^1*, Shin-Ming Huang¹

¹Department of Physics, National Sun Yat-sen University, Kaohsiung, Taiwan

* Presenter:Lasin Abdul Rahman Thaivalappil, email:d102030006@g-mail.nsysu.edu.tw

SmAlSi, a Weyl semimetal, has recently undergone extensive study, unveiling its pronounced quantum anomalous hall effect (QAHE), magnetic-resistance, chiral anomaly, Fermi arcs, and photo galvanic effect. Furthermore, recent neutron scattering findings indicate the presence of a spiral magnetic spin texture which can be mediated by Weyl electrons, positioning it as a prime candidate for spintronic applications. Additionally, Sm can be substituted with heavy-earth metals like Ce and Nd, resulting in large anisotropy, making it ideal for comparative analyses of anisotropic effects on spin texture. This study was concentrated on probing SmAlSi using the TB model. In this work, we develop a theory for interacting $5f$ spins based on the RKKY mechanism. The $5f$ spins on Sm atoms are interacting via $4d$ electrons according to our DFT calculations. Our calculations show that correlation effects in the $4d$ electrons are necessary for the experimental observed magnetic structure. We demonstrate an interaction phase space for different magnetic orders, in which we recapitulate the experimental observed q=(1/3,1/3,0) magnetic order. This research sheds light on the possible skyrmionic-lattice of SmAlSi in the presence of magnetic fields and provides valuable insights for potential applications in the fields of data storage and spintronics.

Keywords: Weyl semimetal, RKKY mechanism, Skyrmionic-lattice, Spin texture