Type-IV Superconductivity Phenomenon: Cooper Pairs with Broken Parity and Spin-Rotational Symmetries in D- and S-wave Singlet Superconductors

Paramagnetic effects are shown to result in the appearance of a triplet component of order parameter in vortex phases of d- and s-wave singlet superconductors in the absence of impurities. This component, which breaks both parity and spin-rotational symmetries of Cooper pairs, is expected to be of the order of unity in a number of modern superconductors such as high-Tc, organic, MgB$_{2}$, and some others. A generic phase diagram of such type-IV superconductors [1], which are singlet ones at H=0 and in the Meissner phase and characterized by singlet-triplet mixed Copper pairs, $\Delta _s +i\Delta _t $, in a vortex phase, is suggested. \newline \newline [1] A.G. Lebed, Physical Review Letters, accepted (2006).