Band structure of Charge Ordered Doped Antiferromagnets

TL;DR

This paper investigates the electronic spectral weight distribution in doped antiferromagnets with charge order, comparing theoretical models to experimental data, and explores how stripe configurations evolve with doping in cuprate materials.

Contribution

It introduces models of stripe and bubble phases that match experimental spectral data and analyzes stripe orientation transitions with doping in cuprates.

Findings

In-phase stripes match experimental spectral weight distributions.

Staircase stripe configurations reproduce photoemission data.

Stripe orientation transitions correlate with doping levels and inter-stripe spacing.

Abstract

We study the distribution of electronic spectral weight in a doped antiferromagnet with various types of charge order and compare to angle resolved photoemission experiments on lightly doped La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) and electron doped Nd$_{2-x}$Ce$_x$CuO$_{4\pm\delta}$. Calculations on in-phase stripe and bubble phases for the electron doped system are both in good agreement with experiment including in particular the existence of in-gap spectral weight. In addition we find that for in-phase stripes, in contrast to anti-phase stripes, the chemical potential is likely to move with doping. For the hole doped system we find that ``staircase'' stripes which are globally diagonal but locally vertical or horizontal can reproduce the photoemission data whereas pure diagonal stripes cannot. We also calculate the magnetic structure factors of such staircase stripes and find that as the stripe separation is decreased with increased doping these evolve from diagonal to vertical separated by a coexistence region. The results suggest that the transition from horizontal to diagonal stripes seen in neutron scattering on underdoped LSCO may be a crossover between a regime where the typical length of straight stripe segments is longer than the inter-stripe spacing to one where it is shorter and that locally the stripes are always aligned with the Cu-O bonds.