Pseudogaps from thermally disordered spin density waves: optical and Hall conductivity

We use the spin-fermion model and an approximation originally introduced in the charge denstiy wave context by Lee, Rice, and Anderson to study the conductivity and the Hall conductivity of two-dimensional systems close to antiferromagnetically ordered states. The electron spectral function reveals a pseudogap. Calculation of the longitudinal and Hall conductivities requires a vertex correction which has a nontrivial structure which we discuss. Results are compared to data and to other calculations.