Quantum critical spin liquids and conformal field theory in 2+1 dimensions

We describe new conformal field theories based on symplectic fermions that can be extrapolated between 2 and 4 dimensions. The critical exponents depend continuously on the number of components N of the fermions and the dimension D. In the context of anti-ferromagnetism, the N=2 theory is proposed to describe a deconfined quantum critical spin liquid corresponding to a transition between a Neel ordered phase and a VBS-like phase.