DEVIATIONS FROM FERMI-LIQUID BEHAVIOR IN (2-DIMENSIONAL QUANTUM ELECTRODYNAMICS AND THE NORMAL-PHASE OF HIGH-T-C SUPERCONDUCTORS(1))

We argue that the gauge-fermion interaction in multiflavor quantum ele ctrodynamics in (2+1) dimensions is responsible for non-Fermi-liquid b ehavior in the infrared, in the sense of leading to the existence of a nontrivial (quasi)fixed point that lies between the trivial fixed poi nt (at infinite momenta) and the region where dynamical symmetry break ing and mass generation occurs. This quasifixed-point structure implie s slowly varying, rather than fixed, couplings in the intermediate reg ime of momenta, a situation which resembles that of (four-dimensional) ''walking technicolor'' models of particle physics. The inclusion of wave-function renormalization yields marginal O(1/N) corrections to th e ''bulk'' non-Fermi-liquid behavior caused by the gauge interaction i n the limit of infinite flavor number. Such corrections lead to the ap pearance of modified critical exponents. In particular, at low tempera tures there appear to be logarithmic scaling violations of the linear resistivity of the system of order O(1/N). The connection with the ano malous normal-state properties of certain condensed-matter systems rel evant for high-temperature superconductivity is briefly discussed. The relevance of the large (flavor) N expansion to the Fermi-liquid probl em is emphasized. As a partial result of our analysis, we point out th e absence of charge-density-wave instabilities from the effective low- energy theory, as a consequence of gauge invariance.