Simulations of convection in ${}^3\mathrm{He}\mathrm{\text{−}}{}^4\mathrm{He}$ mixtures with a negative separation ratio in two-dimensional containers with realistic boundary conditions and moderately large aspect ratio reveal, at supercritical Rayleigh numbers, the existence of “convectons,” i.e., localized states of stationary convection, separated by regions of no convection. The origin and properties of these states are described.

• Received 14 January 2005

DOI:https://doi.org/10.1103/PhysRevLett.95.244501