Ising-model description of the SU(2)_1 quantum critical point in a   dimerized two-leg spin-1/2 ladder
  A nonperturbative analytical description of the SU(2)_1 quantum critical point in an explicitly dimerized two-leg spin-1/2 Heisenberg ladder is presented. It is shown that this criticality essentially coincides with that emerging in a weakly dimerized spin-1 chain with a small Haldane gap. The approach is based on the mapping onto an SO(3)-symmetric model of three strongly coupled quantum Ising chains. This mapping is used to establish the correspondence between all physical fields of the spin ladder and those characterizing the SU(2)_1 criticality at the infrared fixed point. 
Y.-J. Wang (Nanjing University and ICTP,Trieste) and A.A. Nersesyan   (Institute of Physics,Tbilisi, and ICTP,Trieste)