Nodal quasiparticles in stripe ordered superconductors

High temperature superconductors were studied by adiabatic continuity from the quasi-one-dimensional limit. For this purpose, the simple model effective Hamiltonian, H=H*+H′, of a quasi-one-dimensional system which consists of an array of alternating, inequivalent (A and B type) "chains", was used. By studying the perturbative renormalization-group (RG) flows in the vicinity of the decoupled fixed point, as well as the behavior at various anisotropic 2D fixed points, the qualitative phase diagram and the character of the excitations in the limit of small, but nonzero interchain coupling were determined.