We construct models of excitations about a Fermi surface that display
calculable deviations from Fermi liquid behavior in the low-energy limit. They
arise as a consequence of coupling to a Chern-Simons gauge field, whose
fluctations are controlled through a kx1​ interaction. The Fermi
liquid fixed point is shown to be unstable in the infrared for x<1, and an
infrared-stable fixed point is found in a (1−x)-expansion, analogous to the
ϵ-expansion of critical phenomena. x=1 corresponds to Coulomb
interactions, and in this case we find a logarithmic approach to zero coupling.
We describe the low-energy behavior of metals in the universality class of the
new fixed point, and discuss its possible application to the compressible
ν=21​ quantum Hall state and to the normal state of copper-oxide
superconductors.Comment: 24 pages, 2 figures uuencoded at end, use Phyzzx and epsf, PUPT 1438,
IASSNS-HEP 93/8