Electric field tuning of strain-induced quantum emitters in WSe2

Abstract

Generation of spectrally tunable single photon sources at predetermined spatial locations is a key enabling step toward scalable optical quantum technologies. In this regard, semiconducting two dimensional materials, like tungsten diselenide (WSe2), have recently been shown to host optically active quantum emitters that can be strain induced using nanostructured substrates and also be spectrally tuned with electric and magnetic fields. In this work, we employ a van der Waals heterostructure of WSe2, hexagonal boron nitride, and few layer graphene on a nanopillar array to yield electric field tunable single photon emission at locations with induced strain. The quantum emission lines, which have linewidths of hundreds of μeV, can be tuned by several times their linewidths. In contrast to previous reports of decrease in energy of randomly occurring quantum emitters in WSe2, we interestingly find an increase in energies (blueshift) in these strain-induced emitters.