Wave spectra of square-lattice domains in a quasi-two-dimensional binary complex plasma

Domains of the square lattice have been observed in a quasi-two-dimensional binary complex plasma. The longitudinal and transverse modes of the wave spectra were measured. To compare with the experiment, Langevin dynamics simulations of a binary mixture were carried out, where the non-reciprocal interactions between different species were modeled with a point-wake Yukawa potential. A strong dependence of the wave spectra on the relative magnitude of the point-wake charge is revealed.