Split transition in ferromagnetic superconductors

The split superconducting transition of up-spin and down-spin electrons on the background of ferromagnetism is studied within the framework of a recent model that describes the coexistence of ferromagnetism and superconductivity induced by magnetic fluctuations. It is shown that one generically expects the two transitions to be close to one another. This conclusion is discussed in relation to experimental results on URhGe. It is also shown that the magnetic Goldstone modes acquire an interesting structure in the superconducting phase, which can be used as an experimental tool to probe the origin of the superconductivity.