Single Photon Source from a Nanoantenna-Trapped Single Quantum Dot

Abstract

Single photon sources with high brightness and subnanosecond lifetimes are key components for quantum technologies. Optical nanoantennas can enhance the emission properties of single quantum emitters, but this approach requires accurate nanoscale positioning of the source at the plasmonic hotspot. Here, we use plasmonic nanoantennas to simultaneously trap single colloidal quantum dots and enhance their photoluminescence. The nano-optical trapping automatically locates the quantum emitter at the nanoantenna hotspot without further processing. Our dedicated nanoantenna design achieves a high trap stiffness of 0.6 (fN/nm)/mW for quantum dot trapping, together with a relatively low trapping power of 2 mW/μm 2 . The emission from the nanoantennatrapped single quantum dot shows 7× increased brightness, 50× reduced blinking, 2× shortened lifetime, and a clear antibunching below 0.5 demonstrating true single photon emission. Combining nano-optical tweezers with plasmonic enhancement is a promising route for quantum technologies and spectroscopy of single nano-objects.

Coupling Perovskite Quantum Dot Pairs in Solution using a Nanoplasmonic Assembly

“…Aperture based optical tweezers have been used to trap quantum dots, 22 study their emission (also with two photon excitation), 23 and enhance their single photon emission characteristics. 24 We demonstrate that the DNH optical tweezer can be used to determine the sizes of individual PQDs and correlate size with the emission spectra shifts from quantum confinement. We also demonstrate that the DNH tweezer can capture two quantum dots (i.e., assemble them in real-time) and thereby measure the spectral shift that arises from their coupling.…”

“…Here, we use double-nanohole (DNH) optical tweezers to characterize the dispersion of cesium lead bromide (CsPbBr 3 ) PQDs and their coupling in solution. Aperture-based optical tweezers have been used to trap quantum dots, study their emission (also with two-photon excitation), and enhance their single-photon emission characteristics . We demonstrate that the DNH optical tweezer can be used to determine the sizes of individual PQDs and correlate size with the emission spectra shifts from quantum confinement.…”

Nanomaterials for Quantum Information Science and Engineering

“…[489,547,548] ), II-VI colloidal QDs (orange circles, refs. [511][512][513][514] ), perovskites (labeled PVSK, cyan circles, refs. [518,525,533,549] ), and graphene quantum dots (blue star, ref.…”

Future Prospects for Biomolecular Trapping with Nanostructured Metals

“…Similarly, shaped apertures have been used to trap quantum dots and use them as single-photon emitters, as well as to reposition fluorescent beads, by forming the aperture at the end of a tapered fiber. Various shapes have been explored, like rectangles, bowties, ,,,, Fano resonant asymmetric apertures, and coaxial apertures. ,, Even algorithm designed apertures have been realized for improved trapping using the double-nanohole as a starting point .…”