Spin-Orientation Modulation of Topology and Transport in a Breathing-Kagome Weyl Magnet

The manipulation over diverse topological matters has become a critical demand for advancing quantum devices and topological spintronics. However, such experimental demonstrations remain scarce. Here, based on a novel breathing kagome magnetic Weyl semimetal LaCrGe₃, we realize a spin-rotation driven Weyl state evolution under the control of an external magnetic field. While the breathing of kagome lattice is revealed to boost the desired topologic state, the predicted Weyl points are observed around the Fermi level via angle-resolved photoemission spectroscopy, and are further corroborated by transport effects of chiral-anomaly-related negative magnetoresistance and large anomalous Hall conductivity. By rotating the external magnetic field, we demonstrated that the reorientation of magnetic moments can drive the motion of Weyl points in momentum space, which is characterized by a highly tunable angle-dependent Hall response. Our study presents a modulation of both topology and transport via spin orientation that offers fundamental insights for developing next-generation spin-based functional devices based on topological physics.