主讲人简介：德国马普学会地外物理研究所长聘高级科学家、课题组组长。主要从事天体物理、复杂系统、等离子体物理的理论研究。

内容摘要：Complex plasmas, which are composed of a weakly ionized gas and charged microparticles, represent the plasma state of soft matter. The dynamics of individual microparticles in experiments with quasi-two-dimensional (q2D) systems levitating above a horizontal electrode can be easily visualized and measured. These systems have two remarkable features. First, since the surrounding gas is dilute, the short-time dynamics of individual microparticles in strongly coupled complex plasmas is practically undamped. Second, the effective interparticle interactions in q2D complex plasmas violate the action-reaction symmetry: the vertical electric field near the electrode induces a plasma flow, which generates plasma wakes around the levitating microparticles and thus makes their effective electrostatic interactions nonreciprocal. The degree of non-reciprocity can be controlled in experiments, which makes such systems perfectly suited for studying collective out-of-equilibrium phenomena. In my talk I will present experiments illustrating the non-equilibrium behavior, explain the underlying mechanisms, and discuss interesting analogies with non-equilibrium phenomena occurring in regular liquids and solids.

主持人：杜诚然

撰写：李学元