Large Thermal Hall Effect in Spinel FeCr₂S₄

The thermal Hall effect (THE) is an important experimental probe of band topology and elementary excitations. Here, a large thermal Hall angle (THA) kappa(xy)/kappa(xx) approximate to 7 x 10(-3) discovered so far in ferrimagnetic spinel FeCr2S4 and a large thermal Hall conductivity (kappa(xy)) discovered first in spinel structure and reaching a magnitude of kappa(xy) approximate to 1.8 x 10(-2) WK-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.