Spatial subharmonics, irrational patterns, and disorder in eutectic growth

It is shown that in the eutectic system there exist a variety of symmetry breaking steady-state structures emerging from the Jackson-Hunt branch. These are superstructures appearing successively when the wavelength is increased toward the point of minimum undercooling, which seems to be an accumulation point of the bifurcation sequence. In particular, close to minimum undercooling, there are spatially quasiperiodic and disordered patterns. Implications on the wavelength selection puzzle are discussed. This disorder may be viewed as an attractor for spatiotemporal chaos.