Jinsong XuJiaming HeJ.-S. ZhouDanru QuSsu-Yen HuangC. L. Chien2025-01-102025-01-102024-01-03https://scholars.lib.ntu.edu.tw/handle/123456789/724701The observation of the magnon Hall effect (MHE) has relied solely on the challenging measurement of the thermal Hall conductivity. Here, we report a highly sensitive electrical Seebeck contrast method for the observation of MHE in Lu2V2O7/heavy metal heterostructures, which is highly desirable for the exploration of new MHE materials and their applications. Using measuring wires with very different Seebeck coefficients, we established a general method that can separate contributions (e.g., MHE) that generates a lateral temperature drop, from those [e.g., anomalous Nernst effect (ANE) and spin Seebeck effect (SSE)] that generate a lateral electric field. We show that a suitable heavy metal overlayer can eliminate the inherent ANE and SSE signals from the semiconducting Lu2V2O7. The MHE in Lu2V2O7 is quasi-isotropic among crystals with different orientations. In addition to the previously reported transverse MHE under an in-plane temperature gradient, we have uncovered longitudinal MHE under an out-of-plane temperature gradient.journal article10.1103/physrevb.109.l020401