Fig. 2: Temporal coherence probing of excitonic interaction.

a Power-dependent IX photoluminescence (PL) spectrum from Device 1. The low- and high-energy moiré IXs are labelled as P1 and P2, respectively. b Linewidth vs excitation power for P2 emission. Inset: fitted PL spectrum under 730 nm 34 μW excitation. c Coherence time vs excitation power of the P2 emission. Inset: temporal coherence measurement setup. The arrowed lines show the two paths taken by the light. In (b, c), the symbols are the measured values, and the shaded area represents the coherence time uncertainty. The line is the guide for the eye. d Schematic of inhomogeneous broadening reduction by IX-IX repulsion. The dashed grey and solid black lines are the disorder potential at zero and finite IX density, respectively. The disorder potential is screened by the increasing IX density at a higher power. The red and white circles labelled as ‘e’ and ‘h’ represent the electron and hole, respectively.