Dynes-like superconductivity in thin Al films in parallel magnetic fields

Recently, the ubiquitously applicable phenomenological Dynes formula for the tunneling density of states of superconductors has been explained by assuming that the electrons scatter on a random magnetic field due to impurities. In the original derivation, only the magnitude of the field was taken as random, but the direction of the field was assumed to be fixed. Here we show that this assumption can be relaxed, and therefore the concept of Dynes superconductivity is not restricted to systems with a preferred direction in spin space. We also address the question whether thin Al films in parallel magnetic fields can be described as Dynes superconductors.