Explicit four-fold symmetry breaking effect on the vortex lattice in d-wave superconductors

[[abstract]]We use a recently developed effective Ginzberg-Landau equation to study the vortex lattice structure in d-wave superconductors. By introducing explicit four-fold symmetry breaking terms we are able to reproduce the small angle neutron scattering data on YBCO by Keimer et al. A phase diagram is also constructed and shows quite rich structures[[fileno]]2010108010037[[department]]物理