Nodal-antinodal dichotomy and magic doping fractions in a stripe ordered antiferromagnet

TL;DR

This study models stripe-ordered doped antiferromagnets, revealing a dichotomy between delocalized nodal states and localized antinodal states, and identifies doping-dependent effects on resistivity.

Contribution

It introduces a coupled Hubbard ladder model to explore stripe order, uncovering a nodal-antinodal dichotomy and an even-odd charge periodicity effect.

Findings

Nodal states are delocalized and two-dimensional near (rac{rac}{2},rac{rac}{2})

Antinodal states are quasi-one-dimensional and localized near (rac{rac}{2},0)

Charge periodicity exhibits an even-odd effect influencing resistivity variations

Abstract

We study a model of a stripe ordered doped antiferromagnet consisting of coupled Hubbard ladders which can be tuned from quasi-one-dimensional to two-dimensional. We solve for the magnetization and charge density on the ladders by Hartree-Fock theory and find a set of solutions with lightly doped ``spin-stripes'' which are antiferromagnetic and more heavily doped anti-phase ``charge-stripes''. Both the spin- and charge-stripes have electronic spectral weight near the Fermi energy but in different regions of the Brillouin zone; the spin-stripes in the ``nodal'' region, near (\pi/2,\pi/2), and the charge-stripes in the ``antinodal'' region, near (\pi,0). We find a striking dichotomy between nodal and antinodal states in which the nodal states are essentially delocalized and two-dimensional whereas the antinodal states are quasi-one-dimensional, localized on individual charge-stripes. For bond-centered stripes we also find an even-odd effect of the charge periodicity which could explain the non-monotonous variations with doping of the low-temperature resistivity in LSCO