  In this paper we suggest a novel explanation for the alpha-delta transition
in plutonium based on an analogy between the evolution of the actinide ground
state as a function of spin orbit coupling and the behaviour of thin film
superconductors in a magnetic field. The key point is that in metals with a low
carrier density spin-orbit interactions give rise to low energy monopole-like
solitons with quantized spin currents, which play much the same role as
Abrikosov vortices in thin film superconductors. In alpha-plutonium these
solitons form an ordered solid, while in impurity stabilized delta-plutonium
they form a pair condensate.
