Extended Data Fig. 8: In-plane momentum- and real-space distribution of the Wannier-exciton in Bi2Te3.
From: Spin-polarized spatially indirect excitons in a topological insulator
a, In-plane constant energy map at the energy level of the Wannier-exciton signature (E − EDP = 0.305 eV) obtained at the delay time t = 20 ps. The solid black line represent the surface projected BZ. The data are symmetrized assuming six-fold symmetry and focusing only on the intensity buildup. b, 2D Fourier transform of the momentum-resolved photoemission intensity I(kx,ky) recovers the real-space image I(rx,ry), featuring the electron density distribution of the excitonic wavefunction. The high frequency oscillations reflect the hexagonal lattice structure.
