Triplet pairing and upper critical field in the mixed state of d-wave superconductors

We show that an additional triplet component of the order parameter is generated in the vortex phase of the d-wave superconductor. Spatial variations of the triplet component are analyzed for a strong spin-orbit coupling. Corrections to the London equation and an unusual temperature dependence of the upper critical field H(c2)(T) are obtained in the case of the weak spin-orbit coupling.