Purcell enhancement and polarization control of single-photon emitters in monolayer WSe₂ using dielectric...

Two-dimensional (2D) materials have shown great promise as hosts for high-purity deterministic single-photon sources. In the last few years, the underlying physics of single photon emission in 2D materials have been uncovered, and their optical properties have been improved to meet criteria for a variety of quantum technologies and applications. In this work, we take advantage of the unique characteristics of dielectric nanoantennas in manipulating the electromagnetic response on a sub-wavelength scale to localize and control defect-based single-photon emitters (SPEs) in 2D layered materials. We show that dielectric nanoantennas are capable of inducing high Purcell enhancement >20 and therefore brighter single-photon emission, which is characterized by a reduction of the emitters' radiative lifetimes and enhancement of their brightness by more than an order of magnitude. We demonstrate that the sub-wavelength-scale dielectric nanoantennas can be designed to also impose a predetermined strain profile that determines the confinement potential of the SPE, leading to robust control over the optical polarization with up to 94% extinction ratio. The combination of large Purcell enhancement, polarization orientation, and site control through strain engineering demonstrates the advantages and unique capabilities of dielectric nanoantennas for enhancing the quantum optical properties of 2D SPEs for quantum information technologies.