Finite-temperature renormalization-group study of a dissipative gauge theory with fermions Original Research Article

We study finite temperature (T) properties of a two-dimensional system of fermions interacting with a dissipative gauge field. This system is relevant to various strongly correlated electron systems including systems of the quantum Hall effect and high-Tc. superconductors. At T = 0, it is known that this dissipative gauge theory of fermions has a non-trivial infrared fixed point, and fermions exhibit non-Fermi-liquid like behavior. We extend the Wilson-type renormalization-group (RG) study at T = 0 given in our previous paper to the finite-T case. Renormalization constants are explicitly calculated at one-loop order at finite Tand RG equations of running coupling constants are obtained. We perform numerical calculations to solve the RG recursion equations and obtain a flow diagram. In some parameter regions, our results show that the non-Fermi-liquid fixed point at T = 0 becomes unstable by finite-T effects. However, in intermediate energy scales, the behavior of coupling constants is controlled by the non-Fermi-liquid fixed point at T = 0, i.e. the fixed point at T = 0 becomes a saddle point at T ∗ > 0. Physical implications of this phenomenon are discussed.