Maximizing anomalous Hall effect by tuning the Fermi level in simple Weyl semimetal EuCd₂Sb₂

Magnetic Weyl semimetal EuCd₂Sb₂ provides an ideal platform for demonstrating and utilizing intrinsic anomalous Hall effect originating in the Weyl nodes. This is because EuCd₂Sb₂ in the forced ferromagnetic state hosts a simple Weyl-node-related band structure near the Fermi energy. Here we report growth of EuCd₂Sb₂ single-crystalline films by molecular beam epitaxy and observation of large anomalous Hall effect dependent on the carrier density. By approaching the Fermi level to Weyl node energy positions with controlling growth conditions and applying electrostatic gating, the anomalous Hall angle is largely enhanced as compared to previously reported EuCd₂Sb₂ single-crystalline bulk one. As also confirmed by first-principles calculations of intrinsic anomalous Hall conductivity, the observed anomalous Hall effect shows a sharp peak as a function of the carrier density, revealing clear energy dependence of the Weyl-node-based anomalous Hall effect. Our present work paves the way for further exploring the potential of Weyl-node-based exotic magnetotransport using film techniques.