Single Photon Emitters with Polarization and Orbital Angular Momentum Locking in Monolayer Semiconductors

Excitons in monolayer transition metal dichalcoge-nide are endowed with intrinsic valley-orbit coupling between their center-of-mass motion and valley pseudospin. When trapped in a confinement potential, e.g., generated by strain field, we find that intralayer excitons are valley and orbital angular momentum (OAM) entangled. By tuning the trap profile and external magnetic field, one can engineer the exciton states at the ground state and realize a series of valley-OAM entangled states. We further show that the OAM of excitons can be transferred to emitted photons, and these novel exciton states can naturally serve as polarization-OAM locked single photon emitters, which under certain circumstance become polarization-OAM entangled, highly tunable by strain trap and magnetic field. Our proposal demonstrates a novel scheme to generate polarization-OAM locked/entangled photons at the nanoscale with a high degree of integrability and tunability, pointing to exciting opportunities for quantum information applications.

Automated summary

Excitons in monolayer transition metal dichalcogenide are entangled in both valley and orbital angular momentum when confined by a strain field. By tuning the trap profile and magnetic field, the exciton states can be engineered and used as polarization-OAM locked single photon emitters, which can also be entangled under certain conditions and highly tunable by strain trap and magnetic field. This proposal provides a novel scheme for generating polarization-OAM locked/entangled photons at the nanoscale, with high integrability and tunability, promising exciting opportunities for quantum information applications.