Optical properties of quantum emitters hosted by van der Waals materials

Single quantum emitters in van der Waals materials are interesting as bright sources of single photons and potentially as a localized quantum sensors that are sensitive to their local environment at or near a surface. Defects in hexagonal boron nitride (h-BN) and strain-activated single photon emitters in WSe₂ have emerged as two prominent examples. In this presentation I will focus on our efforts to understand the optical properties of these emitters. I’ll describe our studies of isolated h-BN defects as they relate to optical polarization, linewidth, host material origin, and activation mechanism. In strain-activated WSe₂ quantum emitters, a prominent approach to creating localized strain is to drape WSe₂ over a dielectric nanopillar substrate. I’ll describe our recent finding that wrinkles in h-BN/WSe₂ bilayers lead to a cleaner optical spectrum and purer single-photon emission that of a nanopillar-based emitter. This work was done in collaboration with Raphaël Daveau, Kumarasiri Konthasinghe, Nick Jungwirth, Tom Vandekerckhove, Jaehong Choi, Nikhil Mathur, Arunabh Mukerjee, Chitraleema Chakraborty, Liangyu Qiu, Zefang Wang, Jie Shan, Kin Fai Mak, and A. Nick Vamivakas.