Superconductivity and Pseudogap in Quasi-Two-Dimensional Metals around the Antiferromagnetic Quantum Critical Point

TL;DR

This paper investigates spin fluctuations and superconductivity in quasi-two-dimensional metals near the antiferromagnetic quantum critical point, revealing a dome-shaped Tc, pseudogap phenomena, and Fermi arc features, with implications for high-Tc cuprates.

Contribution

It introduces a parameter y0 to measure proximity to the AFQCP and presents phase diagrams and spectral density calculations that connect spin fluctuations to pseudogap and superconductivity phenomena.

Findings

Tc exhibits a dome shape with a maximum at the AFQCP

Pseudogap appears below a certain temperature T* near (pi,0)

Fermi arc-like features are observed in the spectral density

Abstract

Spin fluctuations (SF) and SF-mediated superconductivity (SC) in quasi-two-dimensional metals around the antiferrromagnetic (AF) quantum critical point (QCP) are investigated by using the self-consistent renormalization theory for SF and the strong coupling theory for SC. We introduce a parameter y0 as a measure for the distance from the AFQCP which is approximately proportional to (x-xc), x being the electron (e) or hole (h) doping concentration to the half-filled band and xc being the value at the AFQCP. We present phase diagrams in the T-y0 plane including contour maps of the AF correlation length and AF and SC transition temperatures TN and Tc, respectively. The Tc curve is dome-shaped with a maximum at around the AFQCP. The calculated one-electron spectral density shows a pseudogap in the high-density-of-states region near (pi,0) below around a certain temperature T* and gives a contour map at the Fermi energy reminiscent of the Fermi arc. These results are discussed in comparison with e- and h-doped high-Tc cuprates.