A Phenomenological Theory of The Pseudogap State

TL;DR

This paper proposes a phenomenological Green's function model for the pseudogap state in underdoped cuprates, aligning with ARPES data and highlighting a quantum critical point between RVB spin liquid and Fermi liquid phases.

Contribution

It introduces a new ansatz for the Green's function based on RVB theory, explaining pseudogap phenomena and the transition to Fermi liquid behavior in cuprates.

Findings

Good agreement with ARPES data on underdoped cuprates

Identification of a quantum critical point in the phase diagram

Phenomenological description of the superconducting dome

Abstract

An ansatz is proposed for the coherent part of the single particle Green's function in a doped resonant valence bond (RVB) state by, analogy with the form derived by Konik and coworkers for a doped spin liquid formed by an array of 2-leg Hubbard ladders near half-filling. The parameters of the RVB state are taken from the renormalized mean field theory of Zhang and coworkers for underdoped cuprates. The ansatz shows good agreement with recent angle resolved photoemission (ARPES) on underdoped cuprates and resolves an apparent disagreement with the Luttinger Sum Rule. The transition in the normal state from a doped RVB spin liquid to a standard Landau Fermi liquid, that occurs in the renormalized mean field theory, appears as a quantum critical point characterized by a change in the analytic form of the Green's function. A d-wave superconducting dome surrounding this quantum critical point is introduced phenomenologically. Results are also presented for the Drude weight and tunneling density of states as functions of the hole density.