An article on the SciTechDaily website reports that researchers at the University of Manchester (UK) have succeeded in creating particle-antiparticle pairs in a vacuum using graphene-based devices, something known as the Schwinger effect that has previously only been observed in cosmic events.
The researchers also saw something else unexpected in their experiments. From the article:
“They filled their simulated vacuum with electrons and accelerated them to the maximum velocity allowed by graphene’s vacuum, which is 1/300 of the speed of light. At this point, something seemingly impossible happened: electrons seemed to become superluminous, providing an electric current higher than allowed by general rules of quantum condensed matter physics. The origin of this effect was explained as spontaneous generation of additional charge carriers (holes).”
The research reports can be found in this article in the journal Science:
“Out-of-equilibrium criticalities in graphene superlattices”