Stability of metallic stripes in the extended one-band Hubbard model

TL;DR

This study uses an unrestricted Gutzwiller approximation to analyze stripe stability and orientation in an extended Hubbard model, revealing conditions favoring metallic stripes and phase degeneracies consistent with experimental observations.

Contribution

It demonstrates that the Gutzwiller approximation accurately predicts stripe phases and their degeneracies, improving upon Hartree-Fock results and aligning with experimental data.

Findings

Negative t'/t favors metallic stripes

Diagonal and vertical stripes become degenerate near optimal doping

GA results agree with experiments, unlike Hartree-Fock

Abstract

Based on an unrestricted Gutzwiller approximation (GA) we investigate the stripe orientation and periodicity in an extended one-band Hubbard model. A negative ratio between next-nearest and nearest neighbor hopping t'/t, as appropriate for cuprates, favors partially filled (metallic) stripes for both vertical and diagonal configurations. At around optimal doping diagonal stripes, site centered (SC) and bond centered (BC) vertical stripes become degenerate suggesting strong lateral and orientational fluctuations. We find that within the GA the resulting phase diagram is in agreement with experiment whereas it is not in the Hartree-Fock approximation due to a strong overestimation of the stripe filling. Results are in agreement with previous calculations within the three-band Hubbard model but with the role of SC and BC stripes interchanged.