DFT+U study of magnetic order in doped La$_2$CuO$_4$ crystals

TL;DR

This study uses DFT+U calculations to explore magnetic phases in doped La$_{2-x}$Sr$_x$CuO$_4$, identifying stripe orders as ground states at specific doping levels and analyzing charge and spin distributions.

Contribution

It provides new insights into the magnetic ground states and charge distribution in doped La$_2$CuO$_4$ using advanced computational methods.

Findings

Bond centered stripe is the magnetic ground state at x=1/8 and 1/4

No stable stripe order at x=1/6

Apical oxygen atoms hold a significant part of holes at high doping

Abstract

This article presents the results of several magnetic phases of doped La$_{2-x}$Sr$_x$CuO$_4$ using density-functional theory with an added Hubbard term (DFT+U). Doping factors from $x=0$ to 0.25 were examined. We found that a bond centered stripe is the magnetic ground state for $x=1/8$ and $x=1/4$. No stable stripe order was found for $x=1/6$. Analysis of the electron density revealed that apical oxygen atoms, those located above and below the copper atoms in the CuO$_2$ planes, hold a non negligible part of the holes at large doping and present a small spin polarization. Finally, the charge reorganization caused by the magnetic stripe modulation was studied for bond centered and atom centered stripes.