Near doping-independent pocket area from an antinodal Fermi surface instability in underdoped high temperature superconductors

TL;DR

This paper explains the doping-independent pocket area in underdoped cuprates through an incommensurate antinodal Fermi surface instability, reconciling experimental observations with theoretical models.

Contribution

It introduces a Fermi surface reconstruction scheme with incommensurate density waves and momentum-dependent coupling to explain experimental phenomena in cuprates.

Findings

Fermi surface pockets are doping-independent due to incommensurate nesting.

The model accounts for observed superstructures in scanning tunneling microscopy.

Charge and bond modulations are cooperatively involved.

Abstract

Fermi surface models applied to the underdoped cuprates predict the small pocket area to be strongly dependent on doping whereas quantum oscillations in YBa2Cu3O6+x find precisely the opposite to be true; seemingly at odds with the Luttinger volume. We show that such behavior can be explained by an incommensurate antinodal Fermi surface nesting-type instability; further explaining the doping-dependent superstructures seen in cuprates using scanning tunneling microscopy. We develop a Fermi surface reconstruction scheme involving orthogonal density waves in two-dimensions and show that their incommensurate behavior requires momentum-dependent coupling. A co-operative modulation of the charge and bond-strength is therefore suggested.