Large Thermal Hall Effect in Spinel FeCr2$_2$S4$_4$.

The thermal Hall effect (THE) is an important experimental probe of band topology and elementary excitations. Here, a large thermal Hall angle (THA) κxy/κxx ≈ 7 × 10−3 discovered so far in ferrimagnetic spinel FeCr2S4 and a large thermal Hall conductivity (κxy) discovered first in spinel structure and reaching a magnitude of κxy≈1.8×10−2WK−1m−1$\kappa _{xy} \approx 1.8 \times 10^{-2} \rm {W K^{-1} m^{-1}}$ at 50 K with a small magnetic field of 0.1 T are reported. These results suggest the emergence of nontrivial topological excitations in FeCr2S4. A large THA in spin caloritronics devices means that a small number of excitations can produce a large transverse signal. FeCr2S4 is therefore a potential platform for spintronics‐magnonics applications, and may enhance the knowledge of the thermal Hall effect. [ABSTRACT FROM AUTHOR]