  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/$\mu$m$^2$. The emission from the nanoantenna-trapped single
quantum dot shows 7x increased brightness, 50x reduced blinking, 2x 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.
