Complex plasmas: An interdisciplinary research field

TLDR

Complex (dusty) plasmas consist of a weakly ionized gas and charged microparticles, offering a soft‑matter plasma state with stretched particle timescales, virtually undamped dynamics, and individual particle visualization and manipulation that make them an analog to liquids and solids. The review aims to exploit complex plasmas to study kinetic‑level processes in liquids or solids beyond continuous media, covering regimes from cooperative onset to large strongly coupled systems. The review first highlights basic and emerging physics accessible with complex plasmas, then examines strong‑coupling phenomena in an interdisciplinary context, emphasizing connections to complex fluids and addressing generic liquid and solid‑state issues.

Abstract

Complex (dusty) plasmas are composed of a weakly ionized gas and charged microparticles and represent the plasma state of soft matter. Complex plasmas have several remarkable features: Dynamical time scales associated with microparticles are ``stretched'' to tens of milliseconds, yet the microparticles themselves can be easily visualized individually. Furthermore, since the background gas is dilute, the particle dynamics in strongly coupled complex plasmas is virtually undamped, which provides a direct analogy to regular liquids and solids in terms of the atomistic dynamics. Finally, complex plasmas can be easily manipulated in different ways---also at the level of individual particles. Altogether, this gives us a unique opportunity to go beyond the limits of continuous media and study---at the kinetic level---various generic processes occurring in liquids or solids, in regimes ranging from the onset of cooperative phenomena to large strongly coupled systems. In the first part of the review some of the basic and new physics are highlighted which complex plasmas enable us to study, and in the second (major) part strong coupling phenomena in an interdisciplinary context are examined. The connections with complex fluids are emphasized and a number of generic liquid and solid-state issues are addressed. In summary, application oriented research is discussed.