  We present two 2D lattice models with non-Fermi liquid metallic phases. We
show that the low energy physics of these models is exactly described by a
Fermi sea of fractionalized quasiparticles coupled to a fluctuating U(1) gauge
field. In the first model, the underlying degrees of freedom are spin 1/2
fermions. This model demonstrates that electrons can in principle give rise to
non-Fermi liquid metallic phases. In the second model, the underlying degrees
of freedom are spinless bosons. This model provides a concrete example of a
(non-Fermi liquid) Bose metal. With little modification, it also gives an
example of a critical U(1) symmetric spin liquid.

Strongly Correlated Electrons