  This paper studies the two-channel Kondo lattice in the large-N limit at
half-filling. In this model, the continuous channel-symmetry is spontaneously
broken, forming a channel ferromagnet in which one conduction channel forms a
Kondo insulator, while the other remains conducting. The paper discusses how
this ground-state can be understood using the concept of "order
fractionalization", in which the channel magnetization breaks up into an
emergent spinor order parameter. By integrating out the fermions we derive an
effective action that describes this symmetry breaking and its emergent
collective modes. A remarkable observation is that topological defects in the
order parameter carry a U(1) flux, manifested in the Aharonov-Bohm phase picked
by electrons that orbit the defect. By studying the effective action, we argue
that the phase diagram contains a non-magnetic transition between a large and a
small Fermi surface.
