Fig. 4: Exciton diffusion and incompressibility.
From: Excitonic Mott insulator in a Bose-Fermi-Hubbard system of moiré WS2/WSe2 heterobilayer
Spectrally and spatially resolved diffusion pattern at \({\nu }_{e}=0.73\left.\right({{{{{{{{\rm{V}}}}}}}}}_{{{{{{{{\rm{g}}}}}}}}}=2.34\)V) for low (a) and high (b) I. The dashed rectangle highlights the region where the suppression of diffusion can be observed. c Exciton diffusion length as a function of the gate voltage for a range of νe and for different input intensities. For low νe, the diffusion length increases with I due to exciton repulsive interaction. Upon further filling the moiré lattice, the trend inverts, indicating the optical realization of incompressible states. The inset is a zoom-in of the red dotted rectangle to highlight the reduction of LX1 with increasing I. The error bars represent the standard errors for the diffusion length estimated from the exponential fitting.
