A photonic integrated chip platform for interlayer exciton valley routing

Abstract

Interlayer excitons in two-dimensional semiconductor heterostructures show suppressed electron–hole overlap resulting in longer radiative lifetimes as compared to intralayer excitons. Such tightly bound interlayer excitons are relevant for important optoelectronic applications, including light storage and quantum communication. Their optical accessibility is, however, limited due to their out-of-plane transition dipole moment. In this work, we design a complementary metal–oxide–semiconductor-compatible photonic integrated chip platform for enhanced near-field coupling of these interlayer excitons with the whispering gallery modes of a microresonator, exploiting the high confinement of light in a small modal volume and high-quality factor of the system. Our platform allows for highly selective emission routing via engineering an asymmetric light transmission that facilitates efficient readout and channeling of the excitonic valley state from such systems.