Spin-gapped incoherent metal with preformed pairing in the doped antiferromagnetic Mott insulator

TL;DR

This paper explores the evolution from an antiferromagnetic Mott insulator to a d-wave superconductor, revealing an intermediate spin-gapped incoherent metal with preformed pairing, characterized by a non-Fermi liquid state and stable fixed point.

Contribution

It introduces a new intermediate phase—a spin-gapped incoherent metal with preformed pairing—arising from strong coupling spin fluctuations in doped Mott insulators.

Findings

Identification of a spin-gapped incoherent metal phase

Analysis of single particle spectrum and spin susceptibility

Connection to spin liquid insulator in gauge theory

Abstract

We investigate how the antiferromagnetic Mott insulator evolves into the d-wave BCS superconductor through hole doping. Allowing spin fluctuations in the strong coupling approach, we find a spin-gapped incoherent metal with preformed pairing as an intermediate phase between the antiferromagnetic Mott insulator and d-wave superconductor. This non-Fermi liquid metal is identified with an infrared stable fixed point in the spin-decomposition gauge theory, analogous to the spin liquid insulator in the slave-boson gauge theory. We consider the single particle spectrum and dynamical spin susceptibility in the anomalous metallic phase, and discuss physical implications.