Fast interlayer exciton drift driven by lattice reconstruction in a van der Waals heterobilayer

Modern short-scale information transmission mainly relies on dissipative charge transport, with electrons scattered by defects and phonons, leading to significant power losses. By contrast, excitons-charge-neutral quasiparticles-offer a playground for electro-optical energy-efficient information transduction and processing owing to their extended lifetimes, charge neutrality and efficient electrostatic control. In this work, we report the observation of fast exciton transport in a van der Waals heterostructure over distances exceeding 10 µm, constrained only by the heterostructure finite size. We observe the presence of excitonic potential ramps that leads to long-range rapid exciton drift and enables rapid dilution of the initial exciton population. Our measurements reveal fast exciton propagation, with interlayer exciton drift velocities of approximately 2.66 × 10⁴ m s^-1, within a transport regime that remains robust across a wide range of exciton densities and temperatures up to 150 K. Our work opens avenues for the development of high-speed, energy-efficient excitonic devices, such as field-effect switches and modulators.