Mechanism of formation of half-doped stripes in underdoped cuprates

TL;DR

This study uses a variational Monte-Carlo approach to demonstrate that strong correlations in a t-J model can naturally form half-doped stripes in underdoped cuprates, aligning with experimental observations.

Contribution

It shows that the t-J model with perturbative electron-phonon effects can stabilize half-doped stripes, a novel insight into stripe formation mechanisms.

Findings

Half-doped stripes are most stable in the underdoped region.

Strong correlations alone can produce stripe modulations.

Long-range Coulomb interactions are less influential in stripe formation.

Abstract

Using a variational Monte-Carlo approach with a recently proposed stripe wave function, we showed that the strong correlation included in a t-J-type model has essentially all the necessary ingredients to form these stripes with modulations of charge density, spin magnetization, and pair field. If a perturbative effect of electron-phonon coupling to renormalize the effective mass or the hopping rate of holes is considered with the model, we find the half-doped stripes, which has on the average one half of a hole in one period of charge modulation, to be most stable, energetic wise in the underdoped region, $1/12\leq\delta\leq1/8$. This is in good agreement with the observation in the neutron scattering experiments. We also find long range Coulomb interaction to be less effective in the formation of half-doped stripes.