Blue quantum fog: chiral condensation in quantum helimagnets.

It is shown that a condensation transition involving a chiral order parameter can occur in itinerant helimagnets, in analogy to the transition between the isotropic phase and the phase known as blue fog or blue phase III in cholesteric liquid crystals. It is proposed that such a transition is the explanation for recent neutron scattering results in MnSi. Predictions are made that will allow for experimental tests of this proposal.