Incomplete Meissner effect of triplet superconductivity

The magnetic properties of a triplet superconductor are investigated using a phenomenological Ginzburg-Landau theory. Due to the presence of a paramagnetic term in the free energy arising from the energy required to flip the spins of a triplet pair by the magnetic field, the system does not exhibit a complete Meissner effect below T_c. This paramagnetic contribution to the magnetization is stabilized by the non-linear terms in the free energy, and for certain values of the parameters, can even cancel the diamagnetic term. The results are discussed in terms of the Anderson- Morel and Balian-Werthamer states.