Transport and thermoelectric properties of U3As4

The discovery of materials with exceptionally large Anomalous Hall Angle (AHA) is both

of fundamental interest and technological use, because large AHA is one measure of a large Berry

curvature associated with nontrivial band topology, which may enable efficient charge-

to-spin conversion, enhanced Hall sensor sensitivity, and low-dissipation transport. Uranium

compounds are promising candidates for realizing such responses due to their correlated 5f

electrons and strong spin–orbit coupling, yet systematic studies remain

limited. Here, we report on those properties of the uranium-based ferromagnet U₃As₄, a body-

centered cubic compound with a Curie temperature of 198 K and heavy-fermion character (γ =

83 mJ/K²·mol). Remarkably, U₃As₄ exhibits a giant anomalous Hall angle of more than 40%,

among the largest reported in ferromagnets, and an anomalous Hall conductivity comparable to

Co2MnGa and surpassing many topological ferromagnets. The interplay of correlated 5f states,

strong spin–orbit coupling, and possible topological band features likely drives these exceptional

responses, indicating that U₃As₄ is a fertile platform for exploring topological heavy-fermion

physics and advancing spintronic and thermoelectric applications.