Theory of incommensurate magnetic correlations across the insulator-superconductor transition in underdoped La_{2-x}Sr_xCuO_4

TL;DR

This paper presents a theoretical model explaining the incommensurate magnetic correlations observed in La_{2-x}Sr_xCuO_4 across the insulator-superconductor transition, matching experimental neutron scattering data.

Contribution

It introduces a spiral state model within the t-t'-t''-J framework that accurately describes the magnetic peak shifts at the transition.

Findings

The model reproduces the incommensurate peaks at 45 and 0 degrees.

It explains the peak position change at the insulator-metal transition.

Calculated peak positions agree with experimental data.

Abstract

The main feature in the elastic neutron scattering of La_{2-x}Sr_xCuO_4 is the existence of incommensurate peaks with positions that jump from 45 to 0 degrees at 5% doping. We show that the spiral state of the t-t'-t''-J model with realistic parameters describes this data perfectly. We explain why in the insulator the peak is at 45 degrees while it switches to 0 degrees precisely at the insulator-metal transition. The calculated positions of the peaks are in agreement with the data in both phases.