When a superfluid—such as liquid helium—is set in rotation, vortices appear in which circulation around a closed loop can take only discrete values. Such quantized vortices have now been observed in a solid-state system—a Bose–Einstein condensate made of exciton polaritons.
- K. G. Lagoudakis
- M. Wouters
- B. Deveaud-Plédran