Numerical study of stability and transmission of free-convection boundary layer flows

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Phase diagram of ferrimagnetic ladders with bond-alternation

We study the phase diagram of a 2-leg bond-alternation spin-(1/2, 1) ladder for two different configurations using a quantum renormalization group approach. Although d-dimensional ferrimagnets show gapless behavior, we will explicitly show that the effect of the spin mixing and the bond-alternation can open the possibility for observing an energy gap. We show that the gapless phases of such systems can be equivalent to the 1-dimensional half-integer antiferroamgnets, besides the gapless ferrimagnetic phases. We therefore propose a phase transition between these two gapless phases that can be seen in the parameter space.Comment: 5 pages and 3 ps figures, accepted in Phys. Rev.