Spontaneous, correlation-driven structure formation is one of the most fundamental collective processes in nature. In particular, particle ensembles in externally controlled confinement geometries allow for a systematic investigation of strong correlation and quantum effects over broad ranges of the relevant trap and plasma parameters. An exceptional feature inherent to finite systems is the governing role of symmetry and surface effects leading to similar collective behaviour in physical systems on vastly different length and energy scales. Considering (i) confined complex (dusty) plasmas and (ii) charge asymmetric bilayers, the effective range of the pair interaction emerges as a key quantity taking effect on the self-organized structure formation. Additional interest arises from the possible mass asymmetry of the plasma constituents in bilayers. Translating the results from (unconfined) 3D plasmas to bilayer systems, it is shown that the critical mass ratio required for crystallization of the heavy plasma component can be drastically reduced such that this effect becomes experimentally accessible.
Complex plasma research on the International Space Station