Excitonic Interactions and Mechanism for Ultrafast Interlayer Photoexcited Response in van der Waals Heterostructures
Chen Hu, Mit H. Naik, Yang‐Hao Chan, Steven G. Louie
Abstract
Optical dynamics in van der Waals heterobilayers is of fundamental scientific and practical interest. Based on a time-dependent adiabatic GW approach, we discover a new many-electron (excitonic) channel for converting photoexcited intralayer to interlayer excitations and the associated ultrafast optical responses in heterobilayers, which is conceptually different from the conventional single-particle picture. We find strong electron-hole interactions drive the dynamics and enhance the pump-probe optical responses by an order of magnitude with a rise time of ∼300 fs in MoSe_{2}/WSe_{2} heterobilayers, in agreement with experiment.
Topics & Concepts
van der Waals forceUltrashort pulseElectronAdiabatic processPhysicsExcitonAtomic physicsMaterials scienceChemical physicsCondensed matter physicsQuantum mechanicsLaserMolecule2D Materials and ApplicationsQuantum and electron transport phenomenaGraphene research and applications