a–d Experimental (symbols) and fitted (solid lines) time evolution of \( \sigma _t^2 \). e–h Experimental and fitted time evolution of ∆T at 0 pump-probe separation. n = 1 (a, e), n = 2 (b, f), n = 3 (c, g), and n = 4 (d, h). Pump photon energies are 2.61 eV, 2.32 eV, 2.14 eV, and 2.14 eV for n ranging from 1 to 4, respectively. Probe photon energies are 2.43 eV, 2.18 eV, 2.03 eV, and 1.97 eV for n ranging from 1 to 4, respectively. The error bars indicate the standard error of Gaussian fit of the exciton population spatial profiles.