A dropleton or quantum droplet is an artificial quasiparticle, constituting a collection of electrons and places without them inside a semiconductor. Dropleton is the first known quasiparticle that behaves like a liquid. The creation of dropletons was announced on 26 February 2014 in a Nature article, that presented evidence for the creation of dropletons in an electron–hole plasma inside a gallium arsenide quantum well by ultrashort laser pulses. The existence of dropletons was not predicted before the experiment.
Despite the relatively short lifetime of about 25 picoseconds, the dropletons are stable enough to be studied. Dropletons possess favorable properties for studying quantum mechanics. Dropletons are approximately 200 nanometers wide, the size of the smallest bacteria. This fact offers the hope to the discoverers that they might one day actually see quantum droplets.