Transverse magnetic field and chiral-nonchiral transition in vortex states for nearly B∥ab in chiral p-wave superconductors

On the basis of Eilenberger theory, we study the vortex state when a magnetic field is applied nearly parallel to the ab plane in a chiral p-wave superconductor with a large anisotropy ratio of ab and c, as in Sr2RuO4. We quantitatively estimate the field dependence of the pair potential, magnetization, and flux-line lattice form factor, and study the transition from the chiral p_ state at low fields to the nonchiral p(y) state at high fields. Even for exactly parallel fields to the ab plane, transverse fields exist in the chiral state. The chiral-nonchiral transition disappears when the magnetic field orientation is tilted within 1 degrees from the ab plane. This may be a reason why the experimental detection of this transition is difficult.