Fig. 2: Temperature evolution of band structure and evidence for spin-valley polarization.

a–c ARPES-intensity plots along the ΓK cut measured at T = 40 K, 150 K, and 300 K, respectively, measured with circularly polarized photons of hν = 75 eV. Peaks p1 and p2 are also indicated. d, e Temperature-dependence of EDCs at selected k cuts at k_y = 0.0 (Γ), −1.1 Å⁻¹ (K’), respectively. f Temperature dependence of the peak position for valence-band peaks at E_B ~ 2–2.5 eV at the Γ point (k_y = 0 Å⁻¹) estimated by numerical fittings to the EDCs assuming Voigt peaks and linear background with error bars ± 20 meV. g, h Second-derivative intensity plots of Fig. 2d, e, respectively. i EDCs for ML Cr₂Se₃, obtained at the K and K’ points with C⁺ and C^- polarized lights using hν = 75 eV. Yellow and purple curves represent subtracted EDCs obtained with C⁺ and C^- photons expanded vertically by 5 times. Inset shows the expansion near E_F. One can recognize a clear circular dichroism (CD) associated with spin-valley polarization which reverses its sign between the K and K’ points.