Figure 1: Spin injection into the surface states of SmB₆.

(a) Schematic drawing of device structure and the spin injection and inverse Edelstein effect measurements. (b) Schematic drawing of the spin–momentum locking properties of the topological surface states at the and Г points based on previous photoemission spectroscopy measurements and DFT calculations^34,44. (c) The resistance of the SmB₆ as a function of the temperature. (d) Typical magnetic field dependence of the voltage with various GHz microwave frequencies. The power of the microwave is 100 mW and the temperature is 1.7 K. Inset: the resonance frequency (f) as a function of the resonance magnetic field (H_res). The solid line is a fitted curve based on the Kittel formula, equation (2) in the main text.