New types of order in strongly correlated materials

In this talk I describe composite orders where the order parameters include multi-particle bound states. It is suggested that such type of order can exist in systems such as Kondo lattices where itinerant electrons coexist with local spins. The corresponding models display many features observed in the cuprates. In particular, it is shown that the precursor of composite order is a pseudo gap state with a spin gap and a Fermi surface whose volume is not related to the particle density. ​