Phases, Broken Symmetries, and Goldstone Modes in Helical Magnets

Helical magnets are in many respects electronic analogs of cholesteric liquid crystals.
The prototypical system MnSi has a rich phase diagram that includes a phase of
topological spin textures known as skyrmions. We will discuss the various phases,
the corresponding broken symmetries and the resulting Goldstone modes, and the
observable consequences for the electronic properties.