Stress tensor and current correlators of interacting conformal field   theories in 2+1 dimensions: Fermionic Dirac matter coupled to U(1) gauge   field
  We compute the central charge $C_T$ and universal conductivity $C_J$ of $N_F$ fermions coupled to a $U(1)$ gauge field up to next-to-leading order in the $1/N_F$ expansion. We discuss implications of these precision computations as a diagnostic for response and entanglement properties of interacting conformal field theories for strongly correlated condensed matter phases and conformal quantum electrodynamics in $2+1$ dimensions. 
Yejin Huh and Philipp Strack
cond-mat.str-el cond-mat.quant-gas hep-th