Work

Cascade of magnetic phase transitions and large topological Hall effect in the noncentrosymmetric antiferromagnet Eu 2 Pd 3 Bi 4

Year: 2025

Type: article

Abstract: The interplay between symmetry breaking, spin-orbit coupling, and magnetic frustration in noncentrosymmetric antiferromagnets has emerged as a fertile ground for discovering intertwined topological and quantum phenomena. Here, we report a cascade of magnetic phase transitions and a large topological Hall response in the newly discovered noncentrosymmetric antiferromagnetic (AFM) material Eu 2 Pd 3 Bi 4 with a Neél temperature T N = 7.6 K . Under magnetic fields ( H ) parallel to the c axis, two successive phase transitions at critical fields H 1 and H 2 are observed in magnetization at temperatures below T N , which are attributed to the occurrences of sequential field-induced spin states. A pronounced topological Hall effect signal emerges exclusively within an intermediate field window H 1 < H < H 2 , signifying the formation of topological spin textures. The field-temperature phase diagram mapped via specific heat and magnetoelectric transport measurements incorporates five phase regimes: The paramagnetic state, a high-field polarized state, and three AFM states with distinct spin configurations. Our results identify Eu 2 Pd 3 Bi 4 as a good candidate for scrutinizing sophisticated interplays between magnetic structure and nontrivial band topology.

Source: Physical Review Research

DOI: 10.1103/593c-xp66