Incommensurate Magnetic Orders and Possible Topological Hall Effect in the Square-Net Centrosymmetric EuGa2Al2 System

Published

July 7, 2022

Author(s)

Jaime Moya, Shiming Lei, Eleanor Clements, Caitlin Kengle, Stella Sun, Kevin Allen, Qizhi Li, Y. Peng, Ali Husain, Matteo Mitrano, Matthew Krogstad, Raymond Osborn, Anand Puthirath, Songxue Chi, Lisa Debeer-Schmitt, Jonathan N. Gaudet, P. Abbamonte, Jeffrey Lynn, E. Morosan

Abstract

Neutron diffraction on the centrosymmetric square-net magnet EuGa₂Al₂ reveals multiple incommensurate magnetic states (AFM1,2,3) in zero field. In applied field, a new magnetic phase (A) is identified from magnetization and transport measurements, bounded by two of the H = 0 incommensurate magnetic phases (AFM1,helical and AFM3, cycloidal) with different moment orientations. Moreover, magneto-transport measurements indicate the presence of topological Hall effect, with maximum values in the A phase. Together, these results render EuGa₂Al₂ a material with non-coplanar or topological spin texture in applied field. X-ray diffraction reveals an out-of-plane (OOP) charge density wave (CDW) below TCDW ∼ 50 K while the magnetic propagation vector lies in-plane below TN = 19.5 K. Together this data points to a new route to realizing in-plane non-collinear spin textures through an OOP CDW which may in turn be unstable against the formation of topological spin textures in an applied field.

Citation

Physical Review Letters

Volume

6

Issue

7

Pub Type

Journals

Keywords

topological Hall effect, skyrmion, charge density wave, neutron diffraction, incommensurate magnetism, rare-earth magnetism

Citation

Moya, J. , Lei, S. , Clements, E. , Kengle, C. , Sun, S. , Allen, K. , Li, Q. , Peng, Y. , Husain, A. , Mitrano, M. , Krogstad, M. , Osborn, R. , Puthirath, A. , Chi, S. , Debeer-Schmitt, L. , Gaudet, J. , Abbamonte, P. , Lynn, J. and Morosan, E. (2022), Incommensurate Magnetic Orders and Possible Topological Hall Effect in the Square-Net Centrosymmetric EuGa₂Al₂ System, Physical Review Letters (Accessed October 26, 2025)