Fig. 3: Characterization of spin modulations using spin-polarized STM.

a Drift-corrected STM topograph at 8 T, b dI/dV layer from a DOS map of the same area, and c Spin-resolved magnetic contrast map M(r) obtained by subtracting the dI/dV map in b from its −8 T counterpart. d Fourier transform of the area shown in Supplementary Fig. 5, which was the area used to obtain data in e–i. e Intensities of the three charge modulation peaks from the Fourier transform of STM topographs taken at different fields with a spin-polarized tip. Inset cartoon schematics show spin-polarized tip alignment with external magnetic field. f–h Intensities of the charge modulation peaks \({{{\bf{q}}}}_{2a0}^{1}\), \({{{\bf{q}}}}_{2a0}^{2}\), and \({{{\bf{q}}}}_{2a0}^{3}\) in dI/dV maps as a function of energy for different magnetic fields. i dI/dV spectra of the Se surface at 0 T (black), 10 T (red), and −10 T (blue) taken over the area denoted by a yellow square in Supplementary Fig. 5. j DFT-simulation of the Se-projected density of states summed over the Se surface atoms from a simulation of the Se-terminated surface. STM setup conditions: a V_sample = 50 mV, I_set = 200; b V_sample = 50 mV, I_set = 200, V_exc = 5 mV (rms); e–h V_sample = 50 mV, I_set = 150 pA, V_exc = 5 mV (rms); i V_sample = −200 mV, I_set = 200 pA, V_exc = 2 mV (rms).