Critical exponents for structural transitions in a complex plasma

The critical instability of two dust particles levitating in the complex plasma sheath of a radio-frequency discharge is considered. It is shown that the two-particle system has a critical point where the alignment symmetry is continuously broken as the system parameter is varied. The associated critical exponents are derived and found to belong to the Ising universality class. Another universality class is suggested for symmetry breaking of the confinement in the horizontal and vertical directions.