Theory of spin liquid on the kagome lattice and application to ZnCu$_3$(OH)$_6$Cl$_2$ : Quantum field theory

We study the properties of an algebraic spin liquid on the kagome lattice, which is suggested by projected wavefunction calculations to be the ground state. Various quantities of relevance to ZnCu$_3$(OH)$_6$Cl$_2$ will be discussed, including specific heat, magnetic susceptibility and spin correlations. The role of magnetic impurities in this spin liquid state and the implications for experiments will also be discussed.