Functional renormalization group for d-wave superconductivity in Hubbard type models

TL;DR

This paper uses the functional renormalization group with partial bosonization to study the temperature-dependent properties of d-wave superconductivity in two-dimensional fermion systems, revealing KT-type phase transition characteristics.

Contribution

It introduces a FRG approach with partial bosonization to analyze d-wave superconductivity and identifies KT-type transition features in the model.

Findings

Superconductivity appears below T_c with a gap and anomalous dimension.

At T_c, the superfluid density exhibits a jump.

The transition shows essential scaling indicative of KT behavior.

Abstract

The temperature dependence of d-wave superconducting order for two dimensional fermions with d-wave attraction is investigated by means of the functional renormalization group with partial bosonization. Below the critical temperature T_c we find superconductivity, a gap in the electron propagator and a temperature dependent anomalous dimension. At T_c the renormalized "superfluid density" jumps and the approach to T_c from above is characterized by essential scaling. These features are characteristic for a phase transition of the Kosterlitz-Thouless (KT) type.