Nodal Liquid Theory of the Pseudo-Gap Phase of High-Tc Superconductors

TL;DR

This paper introduces the 'nodal liquid', a novel quantum phase that explains the pseudo-gap state in underdoped high-Tc superconductors, characterized by unique magnetic and electronic properties derived from a dual field theory.

Contribution

It proposes the 'nodal liquid' as a new phase model, derived via a duality transformation, linking superconductivity, antiferromagnetism, and charge order in high-Tc materials.

Findings

Nodal liquid exhibits power-law magnetic order and T-linear spin susceptibility.

It features non-trivial thermal conductivity and charge gaps observable in experiments.

The effective field theory describes the phase's properties and phase transitions.

Abstract

We introduce and study the nodal liquid, a novel zero-temperature quantum phase obtained by quantum-disordering a d-wave superconductor. It has numerous remarkable properties which lead us to suggest it as an explanation of the pseudo-gap state in underdoped high-temperature superconductors. In the absence of impurities, these include power-law magnetic order, a T-linear spin susceptibility, non-trivial thermal conductivity, and two- and one-particle charge gaps, the latter evidenced, e.g. in transport and electron photoemission (which exhibits pronounced fourfold anisotropy inherited from the d-wave quasiparticles). We use a 2+1-dimensional duality transformation to derive an effective field theory for this phase. The theory is comprised of gapless neutral Dirac particles living at the former d-wave nodes, weakly coupled to the fluctuating gauge field of a dual Ginzburg-Landau theory. The nodal liquid interpolates naturally between the d-wave superconductor and the insulating antiferromagnet, and our effective field theory is powerful enough to permit a detailed analysis of a panoply of interesting phenomena, including charge ordering, antiferromagnetism, and d-wave superconductivity. We also discuss the zero-temperature quantum phase transitions which separate the nodal liquid from various ordered phases.