arXiv:0806.0002 · Physical Review B
Renormalization group theory of nematic ordering in d -wave superconductors
Yejin Huh, Subir Sachdev A
Abstract
We examine the quantum theory of the spontaneous breaking of lattice rotation symmetry in $d$-wave superconductors on the square lattice. This is described by a field theory of an Ising nematic order parameter coupled to the gapless fermionic quasiparticles. We determine the structure of the renormalization group to all orders in a $1/{N}_{f}$ expansion, where ${N}_{f}$ is the number of fermion spin components. Asymptotically exact results are obtained for the quantum critical theory in which, as in the large ${N}_{f}$ theory, the nematic order has a large anomalous dimension, and the fermion spectral functions are highly anisotropic.