Complex plasma—the plasma state of soft matter

Complex plasma is the plasma state of soft matter which consists of weakly ionized gas (plasma) and highly charged microparticles. The microparticles are large enough to be visualized individually and their dynamics can be observed with great accuracy using simple video microscopic techniques. These features allow us to perform experiments with high temporal and spatial resolutions. Furthermore, since the background gas is usually dilute, the particle dynamics of strongly coupled complex plasmas are virtually undamped, which provides a direct analogy to regular liquids and solids in terms of the atomistic dynamics. All these unique features allow complex plasma to be used as an ideal model system (complementary to other model systems in soft matter physics such as colloids, granular medium, etc.) to investigate various phenomena (e.g, phase transitions, phase separation, self-organizations, rheology, linear and nonlinear waves, transport, etc.) at the most fundamental kinetic level.