Towards a holographic marginal Fermi liquid
  We present an infinite class of 2+1 dimensional field theories which, after coupling to semi-holographic fermions, exhibit strange metallic behavior in a suitable large $N$ limit. These theories describe lattices of hypermultiplet defects interacting with parity-preserving supersymmetric Chern-Simons theories with $U(N) \times U(N)$ gauge groups at levels $\pm k$. They have dual gravitational descriptions in terms of lattices of probe M2 branes in $AdS_4 \times S^7/Z_k$ (for $N \gg 1, N \gg k^5$) or probe D2 branes in $AdS_4 \times CP^3$ (for $N \gg k \gg 1, N \ll k^5$). We discuss several challenges one faces in maintaining the success of these models at finite $N$, including backreaction of the probes in the gravity solutions and radiative corrections in the weakly coupled field theory limit. 
Kristan Jensen, Shamit Kachru, Andreas Karch, Joseph Polchinski, and   Eva Silverstein
hep-th cond-mat.str-el