Oh, well, of course “photons”. Wake me up when they start teleporting neutrons! (or Volkswagon Beetles)
Unfortunately, though they appear similar (despite the fact that no two have a heater that works -- or fails to work -- in quite the same way) Volkswagons are not indistinguihable particles, so a single state vector cannot describe a system composed of two VW's. This makes them ineligible for QT.
Forget neutrons. I want them transporting Morons.