Fermi surface reconstruction in hole-doped t-J models without long-range antiferromagnetic order

TL;DR

This paper investigates how short-range antiferromagnetic correlations in hole-doped t-J models cause Fermi surface reconstruction into hole pockets without long-range order, proposing a fractionalized Fermi liquid state relevant to cuprates.

Contribution

It demonstrates Fermi surface reconstruction in a regime without long-range order using the spinon-dopon formalism, introducing the FL* state as a potential ground state for underdoped cuprates.

Findings

Fermi surface forms hole pockets not centered at the antiferromagnetic zone boundary.

Fermi surface area scales with dopant density, violating conventional Luttinger theorem.

Identifies a transition from FL* to Fermi liquid with long-range antiferromagnetic order.

Abstract

We calculate the Fermi surface of electrons in hole-doped, extended t-J models on a square lattice in a regime where no long-range antiferromagnetic order is present, and no symmetries are broken. Using the "spinon-dopon" formalism of Ribeiro and Wen, we show that short-range antiferromagnetic correlations lead to a reconstruction of the Fermi surface into hole pockets which are not necessarily centered at the antiferromagnetic Brillouin zone boundary. The Brillouin zone area enclosed by the Fermi surface is proportional to the density of dopants away from half-filling, in contrast to the conventional Luttinger theorem which counts the total electron density. This state realizes a "fractionalized Fermi liquid" (FL*), which has been proposed as a possible ground-state of the underdoped cuprates; we note connections to recent experiments. We also discuss the quantum phase transition from the FL* state to the Fermi liquid state with long-range antiferromagnetic order.