  We study the physics of 3d supersymmetric abelian gauge theories (with small
supersymmetry breaking perturbations) at finite density. Using mirror symmetry,
which provides a natural generalization of the duality between the XY model and
the abelian Higgs model but now including fermionic fields, we see many
dynamical phenomena conjectured to be of relevance in condensed matter systems.
In particular, we find examples of the emergence of a Fermi surface at low
energies from hybridization of fermions localized at magnetic defects at high
energies, as well as fractionalization of charged fermions into spinon-holon
pairs with the concomitant appearance of emergent gauge fields. We also find
dual descriptions for Fermi surfaces coupled to critical bosons, which give
rise to non-Fermi liquids.
