Incommensurability and spin excitations of diagonal stripes in cuprates

TL;DR

This paper uses the Gutzwiller approximation to show that diagonal stripe spin excitations in underdoped lanthanum cuprates can explain neutron scattering data, revealing hourglass dispersion and the role of stripe disorder.

Contribution

It demonstrates that inelastic neutron scattering results can be explained by a mixture of bond and site centered stripes with disorder, using a theoretical model.

Findings

Hourglass dispersion in spin response matches experiments

Crossing of Goldstone and high-energy branches at Ecross

High energy response resembles parent antiferromagnet

Abstract

Based on the time-dependent Gutzwiller approximation we study the possibility that the diagonal incommensurate spin scattering in strongly underdoped lanthanum cuprates originates from antiferromagnetic domain walls (stripes). Calculation of the dynamic spin response for stripes in the diagonal phase yields the characteristic hour glass dispersion with the crossing of low energy Goldstone and high-energy branches at a characteristic energy Ecross at the antiferromagnetic wave-vector Q_{AF}. The high energy part is close to the parent antiferromagnet. Our results suggest that inelastic neutron scattering experiments on strongly underdoped lanthanum cuprates can be understood as due to a mixture of bond centered and site centered stripe configurations with substantial disorder.